CVE-2021-31535
Last modified
CVE-2021-31535 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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). EPSS estimates a 10.63% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| X.Org | Libx11 | < 1.7.1 |
| X.Org | X Window System | <= x11r7.7 |
| Fedoraproject | Fedora | 33 |
References
- http://packetstormsecurity.com/files/162737/libX11-Insufficient-Length-Check-Injection.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2021/May/52Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/05/18/2Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00021.htmlThird Party Advisory
- https://lists.freedesktop.org/archives/xorg/Third Party Advisory
- https://security.gentoo.org/glsa/202105-16Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210813-0001/Third Party Advisory
- https://unparalleled.eu/blog/2021/20210518-using-xterm-to-navigate-the-huge-color-space/Exploit, Third Party Advisory
- https://unparalleled.eu/publications/2021/advisory-unpar-2021-1.txtExploit, Third Party Advisory
- https://www.debian.org/security/2021/dsa-4920Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/05/18/2Mailing List, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/05/18/3Mailing List, Third Party Advisory
- http://packetstormsecurity.com/files/162737/libX11-Insufficient-Length-Check-Injection.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2021/May/52Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/05/18/2Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00021.htmlThird Party Advisory
- https://lists.freedesktop.org/archives/xorg/Third Party Advisory
- https://security.gentoo.org/glsa/202105-16Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210813-0001/Third Party Advisory
- https://unparalleled.eu/blog/2021/20210518-using-xterm-to-navigate-the-huge-color-space/Exploit, Third Party Advisory
- https://unparalleled.eu/publications/2021/advisory-unpar-2021-1.txtExploit, Third Party Advisory
- https://www.debian.org/security/2021/dsa-4920Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/05/18/2Mailing List, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/05/18/3Mailing List, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
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