Remote Code Execution Vulnerability in X.Org X and libX11
CVE-2021-31535

9.8CRITICAL

Key Information:

Vendor

X.org

Status
X Window System
Libx11
Vendor
CVE Published:
27 May 2021

What is CVE-2021-31535?

A vulnerability exists in the libX11 library through versions before 1.7.1, allowing remote attackers to execute arbitrary code via the XLookupColor request. By sending excessively long color-name requests, an attacker can exploit a flaw that interprets the user-controlled data as additional X protocol requests, potentially disabling X server authorization. This can lead to complete control over the victim's graphical session, making it critical for users to update their systems to the latest libX11 version to mitigate this risk.

References

https://unparalleled.eu/publications/2021/advisory-unpar-...
x_refsource_MISC
https://lists.freedesktop.org/archives/xorg/
x_refsource_MISC
http://www.openwall.com/lists/oss-security/2021/05/18/2
mailing-listx_refsource_MLIST

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.