CVEvulnerability

CVE-2021-31535

9.8 CRITICAL Published 2021-05-27 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-05-27
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected])
7.5 HIGH — AV:N/AC:L/Au:N/C:P/I:P/A:P
Weaknesses
CWE-120

Description

LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote attackers to execute arbitrary code. The libX11 XLookupColor request (intended for server-side color lookup) contains a flaw allowing a client to send color-name requests with a name longer than the maximum size allowed by the protocol (and also longer than the maximum packet size for normal-sized packets). The user-controlled data exceeding the maximum size is then interpreted by the server as additional X protocol requests and executed, e.g., to disable X server authorization completely. For example, if the victim encounters malicious terminal control sequences for color codes, then the attacker may be able to take full control of the running graphical session.

Affected configurations

• x.org libx11 (< 1.7.1) • x.org x window system (<= x11r7.7) • fedoraproject fedora 33

Related

Weakness · CWE (1)

  • CWE-120 Buffer Copy without Checking Size of Input weakness

References