CVE-2021-31535: fedoraproject fedora Classic Buffer Overflow

Vulnerability summary

CVE-2021-31535 is a critical (CVSS 9.8) Classic Buffer Overflow vulnerability in fedoraproject fedora. EPSS estimates a 10.63% chance of exploitation in the next 30 days, higher than 95.7% of scored vulnerabilities. 3 public exploits are recorded.

Timeline

1. 27-05-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.