CVE-2020-12423
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one...
7.8 HighFix available
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
0.41%Down 18.0 points since Apr 14, 2021
What each source reports
NVD Score used
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.
- Record
CVE-2020-12423- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.9 Medium
AV:L/AC:M/Au:N/C:C/I:C/A:C - Weakness
- CWE-427
- Updated
- 2026-11-02
CVE List No score
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.
- Record
CVE-2020-12423- Updated
- 2026-11-02
EUVDEUVD-2020-4735 No score
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.
- Record
EUVD-2020-4735- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qj63-c77f-88gh
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one...
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.
- Record
GHSA-qj63-c77f-88gh- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-427
- Updated
- 2026-11-02
OSVALPINE-CVE-2020-12423
When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.
- Record
ALPINE-CVE-2020-12423- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSVopenSUSE-SU-2020:0983-1 No score
Security update for MozillaFirefox
This update for MozillaFirefox to version 78.0.1 ESR fixes the following issues:
Security issues fixed:
- CVE-2020-12415: AppCache manifest poisoning due to url encoded character processing (bsc#1173576).
- CVE-2020-12416: Use-after-free in WebRTC VideoBroadcaster (bsc#1173576).
- CVE-2020-12417: Memory corruption due to missing sign-extension for ValueTags on ARM64 (bsc#1173576).
- CVE-2020-12418: Information disclosure due to manipulated URL object (bsc#1173576).
- CVE-2020-12419: Use-after-free in nsGlobalWindowInner (bsc#1173576).
- CVE-2020-12420: Use-After-Free when trying to connect to a STUN server (bsc#1173576).
- CVE-2020-12402: RSA Key Generation vulnerable to side-channel attack (bsc#1173576).
- CVE-2020-12421: Add-On updates did not respect the same certificate trust rules as software updates (bsc#1173576).
- CVE-2020-12422: Integer overflow in nsJPEGEncoder::emptyOutputBuffer (bsc#1173576).
- CVE-2020-12423: DLL Hijacking due to searching %PATH% for a library (bsc#1173576).
- CVE-2020-12424: WebRTC permission prompt could have been bypassed by a compromised content process (bsc#1173576).
- CVE-2020-12425: Out of bound read in Date.parse() (bsc#1173576).
- CVE-2020-12426: Memory safety bugs fixed in Firefox 78 (bsc#1173576).
- FIPS: MozillaFirefox: allow /proc/sys/crypto/fips_enabled (bsc#1167231).
Non-security issues fixed:
- Fixed interaction with freetype6 (bsc#1173613).
This update was imported from the SUSE:SLE-15:Update update project.
- Record
openSUSE-SU-2020:0983-1- Updated
- 2026-11-02
Show 6 moreShow less
OSVopenSUSE-SU-2020:1017-1 No score
Security update for MozillaFirefox
This update for MozillaFirefox to version 78.0.1 ESR fixes the following issues:
Security issues fixed:
- CVE-2020-12415: AppCache manifest poisoning due to url encoded character processing (bsc#1173576).
- CVE-2020-12416: Use-after-free in WebRTC VideoBroadcaster (bsc#1173576).
- CVE-2020-12417: Memory corruption due to missing sign-extension for ValueTags on ARM64 (bsc#1173576).
- CVE-2020-12418: Information disclosure due to manipulated URL object (bsc#1173576).
- CVE-2020-12419: Use-after-free in nsGlobalWindowInner (bsc#1173576).
- CVE-2020-12420: Use-After-Free when trying to connect to a STUN server (bsc#1173576).
- CVE-2020-12402: RSA Key Generation vulnerable to side-channel attack (bsc#1173576).
- CVE-2020-12421: Add-On updates did not respect the same certificate trust rules as software updates (bsc#1173576).
- CVE-2020-12422: Integer overflow in nsJPEGEncoder::emptyOutputBuffer (bsc#1173576).
- CVE-2020-12423: DLL Hijacking due to searching %PATH% for a library (bsc#1173576).
- CVE-2020-12424: WebRTC permission prompt could have been bypassed by a compromised content process (bsc#1173576).
- CVE-2020-12425: Out of bound read in Date.parse() (bsc#1173576).
- CVE-2020-12426: Memory safety bugs fixed in Firefox 78 (bsc#1173576).
- FIPS: MozillaFirefox: allow /proc/sys/crypto/fips_enabled (bsc#1167231).
Non-security issues fixed:
- Fixed interaction with freetype6 (bsc#1173613).
This update was imported from the SUSE:SLE-15:Update update project.
- Record
openSUSE-SU-2020:1017-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:10600-1 No score
MozillaFirefox-92.0-1.2 on GA media
These are all security issues fixed in the MozillaFirefox-92.0-1.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:10600-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:14572-1 No score
firefox-esr-128.5.1-1.1 on GA media
These are all security issues fixed in the firefox-esr-128.5.1-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:14572-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:14421-1 No score
Security update for MozillaFirefox
This update for MozillaFirefox to version 78.0.1 ESR fixes the following issues:
Security issues fixed:
- CVE-2020-12415: AppCache manifest poisoning due to url encoded character processing (bsc#1173576).
- CVE-2020-12416: Use-after-free in WebRTC VideoBroadcaster (bsc#1173576).
- CVE-2020-12417: Memory corruption due to missing sign-extension for ValueTags on ARM64 (bsc#1173576).
- CVE-2020-12418: Information disclosure due to manipulated URL object (bsc#1173576).
- CVE-2020-12419: Use-after-free in nsGlobalWindowInner (bsc#1173576).
- CVE-2020-12420: Use-After-Free when trying to connect to a STUN server (bsc#1173576).
- CVE-2020-12402: RSA Key Generation vulnerable to side-channel attack (bsc#1173576).
- CVE-2020-12421: Add-On updates did not respect the same certificate trust rules as software updates (bsc#1173576).
- CVE-2020-12422: Integer overflow in nsJPEGEncoder::emptyOutputBuffer (bsc#1173576).
- CVE-2020-12423: DLL Hijacking due to searching %PATH% for a library (bsc#1173576).
- CVE-2020-12424: WebRTC permission prompt could have been bypassed by a compromised content process (bsc#1173576).
- CVE-2020-12425: Out of bound read in Date.parse() (bsc#1173576).
- CVE-2020-12426: Memory safety bugs fixed in Firefox 78 (bsc#1173576).
- FIPS: MozillaFirefox: allow /proc/sys/crypto/fips_enabled (bsc#1167231).
Non-security issues fixed:
- Fixed interaction with freetype6 (bsc#1173613).
- Record
SUSE-SU-2020:14421-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:1898-1 No score
Security update for MozillaFirefox
This update for MozillaFirefox to version 78.0.1 ESR fixes the following issues:
Security issues fixed:
- CVE-2020-12415: AppCache manifest poisoning due to url encoded character processing (bsc#1173576).
- CVE-2020-12416: Use-after-free in WebRTC VideoBroadcaster (bsc#1173576).
- CVE-2020-12417: Memory corruption due to missing sign-extension for ValueTags on ARM64 (bsc#1173576).
- CVE-2020-12418: Information disclosure due to manipulated URL object (bsc#1173576).
- CVE-2020-12419: Use-after-free in nsGlobalWindowInner (bsc#1173576).
- CVE-2020-12420: Use-After-Free when trying to connect to a STUN server (bsc#1173576).
- CVE-2020-12402: RSA Key Generation vulnerable to side-channel attack (bsc#1173576).
- CVE-2020-12421: Add-On updates did not respect the same certificate trust rules as software updates (bsc#1173576).
- CVE-2020-12422: Integer overflow in nsJPEGEncoder::emptyOutputBuffer (bsc#1173576).
- CVE-2020-12423: DLL Hijacking due to searching %PATH% for a library (bsc#1173576).
- CVE-2020-12424: WebRTC permission prompt could have been bypassed by a compromised content process (bsc#1173576).
- CVE-2020-12425: Out of bound read in Date.parse() (bsc#1173576).
- CVE-2020-12426: Memory safety bugs fixed in Firefox 78 (bsc#1173576).
- FIPS: MozillaFirefox: allow /proc/sys/crypto/fips_enabled (bsc#1167231).
Non-security issues fixed:
- Fixed interaction with freetype6 (bsc#1173613).
- Record
SUSE-SU-2020:1898-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:1899-1 No score
Security update for MozillaFirefox
This update for MozillaFirefox to version 78.0.1 ESR fixes the following issues:
Security issues fixed:
- CVE-2020-12415: AppCache manifest poisoning due to url encoded character processing (bsc#1173576).
- CVE-2020-12416: Use-after-free in WebRTC VideoBroadcaster (bsc#1173576).
- CVE-2020-12417: Memory corruption due to missing sign-extension for ValueTags on ARM64 (bsc#1173576).
- CVE-2020-12418: Information disclosure due to manipulated URL object (bsc#1173576).
- CVE-2020-12419: Use-after-free in nsGlobalWindowInner (bsc#1173576).
- CVE-2020-12420: Use-After-Free when trying to connect to a STUN server (bsc#1173576).
- CVE-2020-12402: RSA Key Generation vulnerable to side-channel attack (bsc#1173576).
- CVE-2020-12421: Add-On updates did not respect the same certificate trust rules as software updates (bsc#1173576).
- CVE-2020-12422: Integer overflow in nsJPEGEncoder::emptyOutputBuffer (bsc#1173576).
- CVE-2020-12423: DLL Hijacking due to searching %PATH% for a library (bsc#1173576).
- CVE-2020-12424: WebRTC permission prompt could have been bypassed by a compromised content process (bsc#1173576).
- CVE-2020-12425: Out of bound read in Date.parse() (bsc#1173576).
- CVE-2020-12426: Memory safety bugs fixed in Firefox 78 (bsc#1173576).
- FIPS: MozillaFirefox: allow /proc/sys/crypto/fips_enabled (bsc#1167231).
Non-security issues fixed:
- Fixed interaction with freetype6 (bsc#1173613).
- Record
SUSE-SU-2020:1899-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
firefoxAlpine:v3.12 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.13 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.14 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.15 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.16 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.17 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.18 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.19 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.20 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.21 |
before 78.0-r0 | 78.0-r0 |
Show 51 moreShow less
| Package | Affected | Fixed |
|---|---|---|
firefoxAlpine:v3.22 |
before 78.0-r0 | 78.0-r0 |
firefoxAlpine:v3.23 |
before 78.0-r0 | 78.0-r0 |
librewolfAlpine:v3.21 |
before 78.0-r0 | 78.0-r0 |
librewolfAlpine:v3.22 |
before 78.0-r0 | 78.0-r0 |
librewolfAlpine:v3.23 |
before 78.0-r0 | 78.0-r0 |
librewolfAlpine:v3.24 |
before 78.0-r0 | 78.0-r0 |
MozillaFirefoxSUSE:Linux Enterprise Server 11 SP4-LTSS From an advisory covering 13 CVEs |
before 78.0.1-78.80.2 | 78.0.1-78.80.2 |
MozillaFirefox-branding-SLEDSUSE:Linux Enterprise Server 11 SP4-LTSS From an advisory covering 13 CVEs |
before 78-21.12.1 | 78-21.12.1 |
MozillaFirefoxSUSE:Linux Enterprise Module for Desktop Applications 15 SP1 From an advisory covering 13 CVEs |
before 78.0.1-3.94.2 | 78.0.1-3.94.2 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Module for Desktop Applications 15 SP1 From an advisory covering 13 CVEs |
before 78-4.14.1 | 78-4.14.1 |
MozillaFirefoxSUSE:Linux Enterprise Module for Desktop Applications 15 SP2 From an advisory covering 13 CVEs |
before 78.0.1-3.94.2 | 78.0.1-3.94.2 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Module for Desktop Applications 15 SP2 From an advisory covering 13 CVEs |
before 78-4.14.1 | 78-4.14.1 |
MozillaFirefoxSUSE:HPE Helion OpenStack 8 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:HPE Helion OpenStack 8 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:OpenStack Cloud 7 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:OpenStack Cloud 7 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:OpenStack Cloud 8 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:OpenStack Cloud 8 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:OpenStack Cloud 9 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:OpenStack Cloud 9 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:OpenStack Cloud Crowbar 8 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:OpenStack Cloud Crowbar 8 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:OpenStack Cloud Crowbar 9 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:OpenStack Cloud Crowbar 9 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server for SAP Applications 12 SP2 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server for SAP Applications 12 SP2 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server for SAP Applications 12 SP3 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server for SAP Applications 12 SP3 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server for SAP Applications 12 SP4 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server for SAP Applications 12 SP4 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Software Development Kit 12 SP5 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server 12 SP2-LTSS From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server 12 SP2-LTSS From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server 12 SP2-BCL From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server 12 SP2-BCL From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server 12 SP3-LTSS From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server 12 SP3-LTSS From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server 12 SP3-BCL From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server 12 SP3-BCL From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server 12 SP4-LTSS From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server 12 SP4-LTSS From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server 12 SP5 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server 12 SP5 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Linux Enterprise Server for SAP Applications 12 SP5 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Linux Enterprise Server for SAP Applications 12 SP5 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxSUSE:Enterprise Storage 5 From an advisory covering 14 CVEs |
before 78.0.1-112.3.1 | 78.0.1-112.3.1 |
MozillaFirefox-branding-SLESUSE:Enterprise Storage 5 From an advisory covering 14 CVEs |
before 78-35.3.1 | 78-35.3.1 |
MozillaFirefoxopenSUSE:Leap 15.2 From an advisory covering 13 CVEs |
before 78.0.1-lp152.2.5.1 | 78.0.1-lp152.2.5.1 |
MozillaFirefoxopenSUSE:Leap 15.1 From an advisory covering 13 CVEs |
before 78.0.1-lp151.2.53.1 | 78.0.1-lp151.2.53.1 |
MozillaFirefoxopenSUSE:Tumbleweed From an advisory covering 661 CVEs |
before 92.0-1.2 | 92.0-1.2 |
firefox-esropenSUSE:Tumbleweed From an advisory covering 1860 CVEs |
before 128.5.1-1.1 | 128.5.1-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected, aliases, references | OSV | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-12423 is a high vulnerability (CVSS 7.8) in Mozilla Firefox, published July 8, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 36th percentile. Fixed in firefox 78.0-r0.
References
mozilla.org/security/advisories/mfsa2020-24
bugzilla.mozilla.org/show_bug.cgi?id=1642400
lists.opensuse.org/opensuse-security-announce/2020-07/msg00027.html
nvd.nist.gov/vuln/detail/CVE-2020-12423
github.com/advisories/GHSA-qj63-c77f-88gh
Show 194 moreShow less
security.alpinelinux.org/vuln/CVE-2020-12423
suse.com/support/update/announcement/2020/suse-su-202014421-1
bugzilla.suse.com/1166238
This page doesn't list everything
Left out here: 1,677 references. The JSON record has them.