Fedora
CVE-2021-31535
CRITICAL
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
1DescriptionNVD
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.
AnalysisAI
LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote attackers to execute arbitrary code. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Technical ContextAI
This vulnerability is classified as Buffer Copy without Size Check (CWE-120), which allows attackers to overflow a buffer to corrupt adjacent memory. 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 products include: X.Org Libx11, X.Org X Window System, Fedoraproject Fedora. Version information: before 1.7.1.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Always validate buffer sizes before copy operations. Use bounded functions (strncpy, snprintf). Enable compiler protections.
A flaw was found in xorg-x11-server before 1.20.3. Rated medium severity (CVSS 6.6), this vulnerability is low attack co
An integer overflow vulnerability leading to a double-free was found in libX11. Rated high severity (CVSS 7.8), this vul
"" In X.Org X Server 1.20.4, there is a stack-based buffer overflow in the function XQueryKeymap. Rated high severity (C
Multiple buffer overflows in the (1) XvQueryAdaptors and (2) XvQueryEncodings functions in X.org libXrender before 0.9.1
The XGetImage function in X.org libX11 before 1.6.4 might allow remote X servers to gain privileges via vectors involvin
The XListFonts function in X.org libX11 before 1.6.4 might allow remote X servers to gain privileges via vectors involvi
Multiple integer overflows in libXpm before 3.5.12, when a program requests parsing XPM extensions on a 64-bit platform,
A heap overflow vulnerability exists in X.Org Server and Xwayland where improper memory allocation for logical button ma
X.org libXrandr before 1.5.1 allows remote X servers to trigger out-of-bounds write operations by leveraging mishandling
Multiple integer overflows in X.org libXrandr before 1.5.1 allow remote X servers to trigger out-of-bounds write operati
Format string vulnerability in the LogVHdrMessageVerb function in os/log.c in X.Org X11 1.11 allows attackers to cause a
The (1) XvQueryAdaptors and (2) XvQueryEncodings functions in X.org libXv before 1.0.11 allow remote X servers to trigge
Same weakness CWE-120 – Classic Buffer Overflow
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External POC / Exploit Code
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