CVE-2018-20843

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

Expat is a C library for parsing XML documents.

Security Fix(es):

• expat: large number of colons in input makes parser consume high amount of resources, leading to DoS (CVE-2018-20843)

• expat: heap-based buffer over-read via crafted XML input (CVE-2019-15903)

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.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.3 Release Notes linked from the References section.

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

Expat is a C library for parsing XML documents. The mingw-expat packages provide a port of the Expat library for MinGW.

Security Fix(es):

• expat: large number of colons in input makes parser consume high amount of resources, leading to DoS (CVE-2018-20843)

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.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

• CVE-2017-9233: Fix external entity infinite loop bug
• CVE-2018-20843: Fix extraction of namespace prefix from XML name
• CVE-2019-15903: Deny internal entities closing the doctype (heap overread)

• CVE-2017-9233: Fix external entity infinite loop bug
• CVE-2018-20843: Fix extraction of namespace prefix from XML name
• CVE-2019-15903: Deny internal entities closing the doctype (heap overread)

Updated expat packages fix security vulnerability:

It was discovered that Expat did not properly handled XML input including XML names that contain a large number of colons, potentially resulting in denial of service (CVE-2018-20843).

This update for expat fixes the following issues:

Security issue fixed:

• CVE-2018-20843: Fixed a denial of service triggered by high resource consumption in the XML parser when XML names contain a large amount of colons (bsc#1139937).

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

These are all security issues fixed in the expat-2.4.1-1.2 package on the GA media of openSUSE Tumbleweed.

This update for expat fixes the following issues:

Security issue fixed:

• CVE-2018-20843: Fixed a denial of service triggered by high resource consumption in the XML parser when XML names contain a large amount of colons (bsc#1139937).

This update for expat fixes the following issues:

Security issue fixed:

• CVE-2018-20843: Fixed a denial of service triggered by high resource consumption in the XML parser when XML names contain a large amount of colons (bsc#1139937).

It was discovered that Expat incorrectly handled certain XML files. An attacker could possibly use this issue to cause a denial of service.

USN-4040-1 fixed a vulnerability in expat. This update provides the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM.

Original advisory details:

It was discovered that Expat incorrectly handled certain XML files. An attacker could possibly use this issue to cause a denial of service.

It was discovered that VTK incorrectly handled certain XML files in the embedded Expat library. An attacker could possibly use this issue to cause a denial of service or expose sensitive information.

Tim Boddy, Gustavo Grieco and others discovered that Expat, that is integrated in xmltok library, incorrectly handled certain files. An attacker could possibly use these issues to cause a denial of service, or possibly execute arbitrary code. These issues were only addressed in Ubuntu 16.04 ESM. (CVE-2012-1148, CVE-2015-1283, CVE-2016-0718, CVE-2016-4472, CVE-2018-20843, CVE-2019-15903, CVE-2021-46143, CVE-2022-22822, CVE-2022-22823, CVE-2022-22824, CVE-2022-22825, CVE-2022-22826, CVE-2022-22827)

It was discovered that Expat, that is integrated in xmltok library, incorrectly handled encoding validation of certain files. An attacker could possibly use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2022-25235)

It was discovered that Expat, that is integrated in xmltok library, incorrectly handled namespace URIs of certain files. An attacker could possibly use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2022-25236)

It was discovered that Expat, contained within the xmltok library, incorrectly handled malformed XML data. If a user or application were tricked into opening a crafted XML file, an attacker could cause a denial of service, or possibly execute arbitrary code. (CVE-2015-1283, CVE-2016-0718, CVE-2016-4472, CVE-2019-15903)

It was discovered that Expat, contained within the xmltok library, incorrectly handled XML data containing a large number of colons, which could lead to excessive resource consumption. If a user or application were tricked into opening a crafted XML file, an attacker could possibly use this issue to cause a denial of service. (CVE-2018-20843)

It was discovered that Expat, contained within the xmltok library, incorrectly handled certain input, which could lead to an integer overflow. If a user or application were tricked into opening a crafted XML file, an attacker could possibly use this issue to cause a denial of service. (CVE-2021-46143, CVE-2022-22822, CVE-2022-22823, CVE-2022-22824, CVE-2022-22825, CVE-2022-22826, CVE-2022-22827)