CVE-2021-46143: libexpat_project libexpat Integer Overflow or Wraparound

Vulnerability summary

CVE-2021-46143 is a high (CVSS 8.1) Integer Overflow or Wraparound vulnerability in libexpat_project libexpat. EPSS estimates a 4.46% chance of exploitation in the next 30 days, higher than 91.4% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 06-01-2022
   PublishedVulnerability first disclosed.
2. 14-10-2026
   Last modifiedVulnerability information updated.

Description

In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.

• 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.