CVE-2020-12825

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Last Modified: UTC

Description

A stack overflow flaw was found in libcroco. A service using libcroco's CSS parser could be crashed by a local, authenticated attacker, or an attacker utilizing social engineering, using a crafted input. The highest threat from this vulnerability is to system availability.

Statement

While Red Hat Enterprise Linux 6, 7 and 8 ship versions of libcroco that are vulnerable to this flaw, the packages which use this library as a dependency would require a user to open a malicious file locally for exploitation. Opening such a file may result in a temporary crash of the application. See below for more detailed information:

  • Red Hat Enterprise Linux 8 - libcroco is a runtime dependency of gnome-shell, gettext and inkscape.
  • Red Hat Enterprise Linux 7 - libcroco is a runtime dependency of gnome-shell, gettext, librsvg2 and inkscape.
  • Red Hat Enterprise Linux 6 - libcroco is required by firefox to bundle gtk3 but firefox does not use libcroco as its CSS parsing engine or provide gtk3 to other packages, and thus not affected. libcroco is a runtime dependency of inkscape, librsvg2 and gettext.

This flaw has only been demonstrated to cause a crash, but if there is any concern of further exploitation beyond that, Red Hat Enterprise Linux 6, 7, and 8 packages are built with a stack protector and stack ASLR which would significantly reduce the likelihood of further exploitation.

Mitigation

To mitigate this flaw as it applies to gnome-shell, do not install untrusted gnome-shell extensions or themes. Red Hat Enterprise Linux does not ship with gnome-shell themes that will trigger this vulnerability. To mitigate this flaw as it applies to inkscape, do not open untrusted CSS in inkscape.

Additional Information

External References

Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2020-12825

Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2020-12825

Affected Packages and Issued Red Hat Security Errata

Products / Services Components State Errata
Red Hat Enterprise Linux 5 libcroco Out of support scope
Red Hat Enterprise Linux 6 gettext Out of support scope
Red Hat Enterprise Linux 6 inkscape Out of support scope
Red Hat Enterprise Linux 6 libcroco Out of support scope
Red Hat Enterprise Linux 7 inkscape Fix deferred
Red Hat Enterprise Linux 7 libcroco Fixed RHSA-2020:4072
Red Hat Enterprise Linux 7 gettext Not affected
Red Hat Enterprise Linux 8 inkscape Fix deferred
Red Hat Enterprise Linux 8 libcroco Fixed RHSA-2020:3654
Red Hat Enterprise Linux 8 gettext Not affected
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).

CVSS v3 Score Breakdown Red Hat NVD
CVSS v3 Base Score 7.1 7.1
Attack Vector Network Network
Attack Complexity Low Low
Privileges Required None None
User Interaction Required Required
Scope Unchanged Unchanged
Confidentiality Impact None None
Integrity Impact Low Low
Availability Impact High High

CVSS v3 Vector

Red Hat CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

NVD CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

Red Hat CVSS v3 Score Explanation

Unlimited recursion in this case causes a DoS - there is no demonstrated loss of confidentiality, and a low compromise to integrity due to data modification having limited impact outside of the DoS.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

For open source software shipped by multiple vendors, the CVSS base scores may vary for each vendor's version depending on the version they ship, how they ship it, the platform, and even how the software is compiled. This makes scoring of vulnerabilities difficult for third-party vulnerability databases such as NVD that only provide a single CVSS base score for each vulnerability. Red Hat scores reflect how a vulnerability affects our products specifically.

For more information, see https://access.redhat.com/solutions/762393.

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

  • "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
  • "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.

What can I do if my product is listed as "Will not fix"?

A "will not fix" status means that a fix for an affected product version is not planned or not possible due to complexity, which may create additional risk.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.

What can I do if my product is listed as "Fix deferred"?

A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
  • Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.

What is a mitigation?

A mitigation is an action that can be taken to reduce the impact of a security vulnerability, without deploying any fixes.

I have a Red Hat product but it is not in the above list, is it affected?

The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

In order to maintain code stability and compatibility, Red Hat usually does not rebase packages to entirely new versions. Instead, we backport fixes and new features to an older version of the package we distribute. This can result in some security scanners that only consider the package version to report the package as vulnerable. To avoid this, we suggest that you use an approved vulnerability scanner from our This content is not included.Red Hat Vulnerability Scanner Certification program.

My product is listed as "Out of Support Scope". What does this mean?

When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.