CVE-2020-28020: exim Integer Overflow or Wraparound

Vulnerability summary

CVE-2020-28020 is a critical (CVSS 9.8) Integer Overflow or Wraparound vulnerability in exim. EPSS estimates a 7.94% chance of exploitation in the next 30 days, higher than 94.6% of scored vulnerabilities.

Timeline

1. 06-05-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

Exim 4 before 4.92 allows Integer Overflow to Buffer Overflow, in which an unauthenticated remote attacker can execute arbitrary code by leveraging the mishandling of continuation lines during header-length restriction.

• 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.