CVE-2021-29946: mozilla firefox Integer Overflow or Wraparound

Vulnerability summary

CVE-2021-29946 is a high (CVSS 8.8) Integer Overflow or Wraparound vulnerability in mozilla firefox. EPSS estimates a 1.30% chance of exploitation in the next 30 days, higher than 70% of scored vulnerabilities.

Timeline

1. 24-06-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

Description

Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.