CVE-2021-29980

Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Mozilla Firefox is a standalone web browser, designed for standards compliance and performance. Its functionality can be enhanced via a plethora of extensions.

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance and portability.

Security Fix(es):

Mozilla developers reported memory safety bugs present in Firefox for Android 79. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 80, Firefox ESR < 78.2, Thunderbird < 78.2, and Firefox for Android < 80.(CVE-2020-15670)

Mozilla developers reported memory safety bugs present in Firefox 80 and Firefox ESR 78.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.(CVE-2020-15673)

Mozilla developers reported memory safety bugs present in Firefox 80. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 81.(CVE-2020-15674)

When processing surfaces, the lifetime may outlive a persistent buffer leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 81.(CVE-2020-15675)

If a valid external protocol handler was referenced in an image tag, the resulting broken image size could be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to successfully probe whether an external protocol handler was registered. This vulnerability affects Firefox < 82.(CVE-2020-15680)

When multiple WASM threads had a reference to a module, and were looking up exported functions, one WASM thread could have overwritten another's entry in a shared stub table, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 82.(CVE-2020-15681)

When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose what application to open it in. An attacker could induce that prompt to be associated with an origin they didn't control, resulting in a spoofing attack. This was fixed by changing external protocol prompts to be tab-modal while also ensuring they could not be incorrectly associated with a different origin. This vulnerability affects Firefox < 82.(CVE-2020-15682)

Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.4, Firefox < 82, and Thunderbird < 78.4.(CVE-2020-15683)

Mozilla developers reported memory safety bugs present in Firefox 81. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 82.(CVE-2020-15684)

Side-channel information leakage in graphics in Google Chrome prior to 87.0.4280.66 allowed a remote attacker to leak cross-origin data via a crafted HTML page.(CVE-2020-16012)

Use after free in WebRTC in Google Chrome prior to 88.0.4324.96 allowed a remote attacker to potentially exploit heap corruption via a crafted SCTP packet.(CVE-2020-16044)

In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.(CVE-2020-26950)

(CVE-2020-26951)

(CVE-2020-26953) …

Mozilla Firefox is a standalone web browser, designed for standards compliance and performance. Its functionality can be enhanced via a plethora of extensions.

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance and portability.

Security Fix(es):

Mozilla developers reported memory safety bugs present in Firefox for Android 79. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 80, Firefox ESR < 78.2, Thunderbird < 78.2, and Firefox for Android < 80.(CVE-2020-15670)

Mozilla developers reported memory safety bugs present in Firefox 80 and Firefox ESR 78.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.(CVE-2020-15673)

Mozilla developers reported memory safety bugs present in Firefox 80. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 81.(CVE-2020-15674)

When processing surfaces, the lifetime may outlive a persistent buffer leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 81.(CVE-2020-15675)

If a valid external protocol handler was referenced in an image tag, the resulting broken image size could be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to successfully probe whether an external protocol handler was registered. This vulnerability affects Firefox < 82.(CVE-2020-15680)

When multiple WASM threads had a reference to a module, and were looking up exported functions, one WASM thread could have overwritten another's entry in a shared stub table, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 82.(CVE-2020-15681)

When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose what application to open it in. An attacker could induce that prompt to be associated with an origin they didn't control, resulting in a spoofing attack. This was fixed by changing external protocol prompts to be tab-modal while also ensuring they could not be incorrectly associated with a different origin. This vulnerability affects Firefox < 82.(CVE-2020-15682)

Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.4, Firefox < 82, and Thunderbird < 78.4.(CVE-2020-15683)

Mozilla developers reported memory safety bugs present in Firefox 81. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 82.(CVE-2020-15684)

Side-channel information leakage in graphics in Google Chrome prior to 87.0.4280.66 allowed a remote attacker to leak cross-origin data via a crafted HTML page.(CVE-2020-16012)

Use after free in WebRTC in Google Chrome prior to 88.0.4324.96 allowed a remote attacker to potentially exploit heap corruption via a crafted SCTP packet.(CVE-2020-16044)

In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.(CVE-2020-26950)

(CVE-2020-26951)

(CVE-2020-26953) …

Mozilla Thunderbird is a standalone mail and newsgroup client.

This update upgrades Thunderbird to version 78.13.0.

Security Fix(es):

• Mozilla: Uninitialized memory in a canvas object could have led to memory corruption (CVE-2021-29980)

• Mozilla: Incorrect instruction reordering during JIT optimization (CVE-2021-29984)

• Mozilla: Race condition when resolving DNS names could have led to memory corruption (CVE-2021-29986)

• Mozilla: Memory corruption as a result of incorrect style treatment (CVE-2021-29988)

• Mozilla: Memory safety bugs fixed in Thunderbird 78.13 (CVE-2021-29989)

• Mozilla: Use-after-free media channels (CVE-2021-29985)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

This update upgrades Firefox to version 78.13.0 ESR.

Security Fix(es):

• Mozilla: Uninitialized memory in a canvas object could have led to memory corruption (CVE-2021-29980)

• Mozilla: Incorrect instruction reordering during JIT optimization (CVE-2021-29984)

• Mozilla: Race condition when resolving DNS names could have led to memory corruption (CVE-2021-29986)

• Mozilla: Memory corruption as a result of incorrect style treatment (CVE-2021-29988)

• Mozilla: Memory safety bugs fixed in Thunderbird 78.13 (CVE-2021-29989)

• Mozilla: Use-after-free media channels (CVE-2021-29985)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Updated firefox packages fix security vulnerabilities:

Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash (CVE-2021-29980).

Instruction reordering during JIT optimization resulted in a sequence of instructions that would cause an object to be incorrectly considered during garbage collection. This led to memory corruption and a potentially exploitable crash (CVE-2021-29984).

A use-after-free vulnerability in media channels could have led to memory corruption and a potentially exploitable crash (CVE-2021-29985).

A suspected race condition when calling getaddrinfo while resolving DNS names could have led to memory corruption and a potentially exploitable crash (CVE-2021-29986).

Firefox incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash (CVE-2021-29988).

Mozilla developers Christoph Kerschbaumer, Simon Giesecke, Sandor Molnar, and Olli Pettay reported memory safety bugs present in Firefox ESR 78.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code (CVE-2021-29989).

Updated thunderbird packages fix security vulnerabilities:

Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash (CVE-2021-29980).

Instruction reordering during JIT optimization resulted in a sequence of instructions that would cause an object to be incorrectly considered during garbage collection. This led to memory corruption and a potentially exploitable crash (CVE-2021-29984).

A use-after-free vulnerability in media channels could have led to memory corruption and a potentially exploitable crash (CVE-2021-29985).

A suspected race condition when calling getaddrinfo while resolving DNS names could have led to memory corruption and a potentially exploitable crash (CVE-2021-29986).

Thunderbird incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash (CVE-2021-29988).

Mozilla developers Christoph Kerschbaumer, Simon Giesecke, Sandor Molnar, and Olli Pettay reported memory safety bugs present in Thunderbird ESR 78.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code (CVE-2021-29989).

This update for MozillaFirefox fixes the following issues:

Firefox Extended Support Release 78.13.0 ESR (MFSA 2021-34, bsc#1188891):

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Firefox 91 and Firefox ESR 78.13

This update was imported from the SUSE:SLE-15-SP2:Update update project.

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.2.0 ESR.

Firefox Extended Support Release 91.2.0 ESR

• Fixed: Various stability, functionality, and security fixes MFSA 2021-45 (bsc#1191332)

• CVE-2021-38496: Use-after-free in MessageTask

• CVE-2021-38497: Validation message could have been overlaid on another origin

• CVE-2021-38498: Use-after-free of nsLanguageAtomService object

• CVE-2021-32810: Data race in crossbeam-deque

  https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-pqqp-xmhj-wgcw)

• CVE-2021-38500 (bmo#1725854, bmo#1728321) Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2

• CVE-2021-38501 (bmo#1685354, bmo#1715755, bmo#1723176) Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

• Fixed crash in FIPS mode (bsc#1190710)

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox Extended Support Release 91.0.1 ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster…

This update for MozillaFirefox fixes the following issues:

Firefox Extended Support Release 78.13.0 ESR (MFSA 2021-34, bsc#1188891):

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Firefox 91 and Firefox ESR 78.13

This update for MozillaThunderbird fixes the following issues:

Update to version 78.13 (MFSA 2021-35, bsc#1188891)

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Thunderbird 78.13

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.2.0 ESR.

Firefox Extended Support Release 91.2.0 ESR

• Fixed: Various stability, functionality, and security fixes MFSA 2021-45 (bsc#1191332)

• CVE-2021-38496: Use-after-free in MessageTask

• CVE-2021-38497: Validation message could have been overlaid on another origin

• CVE-2021-38498: Use-after-free of nsLanguageAtomService object

• CVE-2021-32810: Data race in crossbeam-deque

  https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-pqqp-xmhj-wgcw)

• CVE-2021-38500 (bmo#1725854, bmo#1728321) Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2

• CVE-2021-38501 (bmo#1685354, bmo#1715755, bmo#1723176) Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

• Fixed crash in FIPS mode (bsc#1190710)

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox Extended Support Release 91.0.1 ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster…

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.2.0 ESR.

Release 91.2.0 ESR:

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-45 (bsc#1191332):

• CVE-2021-38496: Use-after-free in MessageTask
• CVE-2021-38497: Validation message could have been overlaid on another origin
• CVE-2021-38498: Use-after-free of nsLanguageAtomService object
• CVE-2021-32810: Fixed Data race in crossbeam-deque
• CVE-2021-38500: Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2
• CVE-2021-38501: Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

• Fixed crash in FIPS mode (bsc#1190710)

Release 91.1.0 ESR:

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Release 91.0.1esr ESR:

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test). If you are on a new Apple device, follow these steps to upgrade to the latest Firefox. -…

These are all security issues fixed in the MozillaFirefox-92.0-1.2 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the MozillaThunderbird-91.1.1-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the firefox-esr-128.5.1-1.1 package on the GA media of openSUSE Tumbleweed.

This update for MozillaFirefox fixes the following issues:

Firefox Extended Support Release 78.13.0 ESR (MFSA 2021-34, bsc#1188891):

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Firefox 91 and Firefox ESR 78.13

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.1.0 ESR.

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox 91.0.1esr ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test). If you are on a new Apple device, follow these steps to upgrade to the latest Firefox.
  • Pinch zooming will now be supported for our users with Windows touchscreen devices and touchpads on Mac devices. Firefox users may now use pinch to zoom on touch-capable devices to zoom in and out of webpages.
  • We’ve improved functionality and design for a number of Firefox search features:
    • Selecting a search engine at the bottom of the search panel now enters search mode for that engine, allowing you to see suggestions (if available) for your search terms. The old behavior (immediately performing a search) is available with a shift-click. *…

This update for MozillaFirefox, rust-cbindgen fixes the following issues:

MozillaFirefox was updated to Extended Support Release 91.2.0 ESR

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-45 (bsc#1191332)

• CVE-2021-38496: Use-after-free in MessageTask
• CVE-2021-38497: Validation message could have been overlaid on another origin
• CVE-2021-38498: Use-after-free of nsLanguageAtomService object
• CVE-2021-32810: Data race in crossbeam-deque
• CVE-2021-38500: Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2
• CVE-2021-38501: Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

• Fixed crash in FIPS mode (bsc#1190710)

Firefox Extended Support Release 91.1.0 ESR

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274)

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox 91.0.1esr ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404) (bmo#1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369) (bmo#1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:
  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test).…

This update for MozillaFirefox fixes the following issues:

Firefox Extended Support Release 78.13.0 ESR (MFSA 2021-34, bsc#1188891):

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Firefox 91 and Firefox ESR 78.13

This update for MozillaFirefox fixes the following issues:

Firefox Extended Support Release 78.13.0 ESR (MFSA 2021-34, bsc#1188891):

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Firefox 91 and Firefox ESR 78.13

This update for MozillaFirefox fixes the following issues:

Firefox Extended Support Release 78.13.0 ESR (MFSA 2021-34, bsc#1188891):

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Firefox 91 and Firefox ESR 78.13

This update for MozillaThunderbird fixes the following issues:

Update to version 78.13 (MFSA 2021-35, bsc#1188891)

• CVE-2021-29986: Race condition when resolving DNS names could have led to memory corruption
• CVE-2021-29988: Memory corruption as a result of incorrect style treatment
• CVE-2021-29984: Incorrect instruction reordering during JIT optimization
• CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
• CVE-2021-29985: Use-after-free media channels
• CVE-2021-29989: Memory safety bugs fixed in Thunderbird 78.13

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.1.0 ESR.

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox 91.0.1esr ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test). If you are on a new Apple device, follow these steps to upgrade to the latest Firefox.
  • Pinch zooming will now be supported for our users with Windows touchscreen devices and touchpads on Mac devices. Firefox users may now use pinch to zoom on touch-capable devices to zoom in and out of webpages.
  • We’ve improved functionality and design for a number of Firefox search features:
    • Selecting a search engine at the bottom of the search panel now enters search mode for that engine, allowing you to see suggestions (if available) for your search terms. The old behavior (immediately performing a search) is available with a shift-click. *…

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.2.0 ESR.

Firefox Extended Support Release 91.2.0 ESR

• Fixed: Various stability, functionality, and security fixes MFSA 2021-45 (bsc#1191332)

• CVE-2021-38496: Use-after-free in MessageTask

• CVE-2021-38497: Validation message could have been overlaid on another origin

• CVE-2021-38498: Use-after-free of nsLanguageAtomService object

• CVE-2021-32810: Data race in crossbeam-deque

  https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-pqqp-xmhj-wgcw)

• CVE-2021-38500 (bmo#1725854, bmo#1728321) Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2

• CVE-2021-38501 (bmo#1685354, bmo#1715755, bmo#1723176) Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

• Fixed crash in FIPS mode (bsc#1190710)

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox Extended Support Release 91.0.1 ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster…

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.2.0 ESR.

Release 91.2.0 ESR:

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-45 (bsc#1191332):

• CVE-2021-38496: Use-after-free in MessageTask
• CVE-2021-38497: Validation message could have been overlaid on another origin
• CVE-2021-38498: Use-after-free of nsLanguageAtomService object
• CVE-2021-32810: Fixed Data race in crossbeam-deque
• CVE-2021-38500: Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2
• CVE-2021-38501: Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

• Fixed crash in FIPS mode (bsc#1190710)

Release 91.1.0 ESR:

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Release 91.0.1esr ESR:

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test). If you are on a new Apple device, follow these steps to upgrade to the latest Firefox. -…

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.1.0 ESR.

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox 91.0.1esr ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test). If you are on a new Apple device, follow these steps to upgrade to the latest Firefox.
  • Pinch zooming will now be supported for our users with Windows touchscreen devices and touchpads on Mac devices. Firefox users may now use pinch to zoom on touch-capable devices to zoom in and out of webpages.
  • We’ve improved functionality and design for a number of Firefox search features:
    • Selecting a search engine at the bottom of the search panel now enters search mode for that engine, allowing you to see suggestions (if available) for your search terms. The old behavior (immediately performing a search) is available with a shift-click. *…

This update for MozillaFirefox fixes the following issues:

This update contains the Firefox Extended Support Release 91.1.0 ESR.

• Fixed: Various stability, functionality, and security fixes

MFSA 2021-40 (bsc#1190269, bsc#1190274):

• CVE-2021-38492: Navigating to mk: URL scheme could load Internet Explorer
• CVE-2021-38495: Memory safety bugs fixed in Firefox 92 and Firefox ESR 91.1

Firefox 91.0.1esr ESR

• Fixed: Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed: Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to- tab results in the address bar panel (bug 1720369)
• Fixed: Various stability fixes
• Fixed: Security fix MFSA 2021-37 (bsc#1189547)
• CVE-2021-29991 (bmo#1724896) Header Splitting possible with HTTP/3 Responses

Firefox Extended Support Release 91.0 ESR

• New: Some of the highlights of the new Extended Support Release are:

  • A number of user interface changes. For more information, see the Firefox 89 release notes.
  • Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
  • On Windows, updates can now be applied in the background while Firefox is not running.
  • Firefox for Windows now offers a new page about:third-party to help identify compatibility issues caused by third-party applications
  • Version 2 of Firefox's SmartBlock feature further improves private browsing. Third party Facebook scripts are blocked to prevent you from being tracked, but are now automatically loaded 'just in time' if you decide to 'Log in with Facebook' on any website.
  • Enhanced the privacy of the Firefox Browser's Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companis from using cookies to track your browsing across sites. This feature was originally launched in Firefox's ETP Strict mode.
  • PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.
  • You'll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
  • Improved Print functionality with a cleaner design and better integration with your computer's printer settings.
  • Firefox now protects you from supercookies, a type of tracker that can stay hidden in your browser and track you online, even after you clear cookies. By isolating supercookies, Firefox prevents them from tracking your web browsing from one site to the next.
  • Firefox now remembers your preferred location for saved bookmarks, displays the bookmarks toolbar by default on new tabs, and gives you easy access to all of your bookmarks via a toolbar folder.
  • Native support for macOS devices built with Apple Silicon CPUs brings dramatic performance improvements over the non- native build that was shipped in Firefox 83: Firefox launches over 2.5 times faster and web apps are now twice as responsive (per the SpeedoMeter 2.0 test). If you are on a new Apple device, follow these steps to upgrade to the latest Firefox.
  • Pinch zooming will now be supported for our users with Windows touchscreen devices and touchpads on Mac devices. Firefox users may now use pinch to zoom on touch-capable devices to zoom in and out of webpages.
  • We’ve improved functionality and design for a number of Firefox search features:
    • Selecting a search engine at the bottom of the search panel now enters search mode for that engine, allowing you to see suggestions (if available) for your search terms. The old behavior (immediately performing a search) is available with a shift-click. *…

Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, trick a user into accepting unwanted permissions, or execute arbitrary code.

It was discovered that Thunderbird didn't ignore IMAP server responses prior to completion of the STARTTLS handshake. A person-in-the-middle could potentially exploit this to trick Thunderbird into showing incorrect information. (CVE-2021-29969)

Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, or execute arbitrary code. (CVE-2021-29970, CVE-2021-29976, CVE-2021-29980, CVE-2021-29984, CVE-2021-29985, CVE-2021-29986, CVE-2021-29988, CVE-2021-29989, CVE-2021-30547)