CVE-2021-27433: arm mbed_ualloc Integer Overflow or Wraparound

Vulnerability summary

CVE-2021-27433 is a critical (CVSS 9.8) Integer Overflow or Wraparound vulnerability in arm mbed_ualloc. EPSS estimates a 1.79% chance of exploitation in the next 30 days, higher than 78% of scored vulnerabilities.

Timeline

1. 03-05-2022
   PublishedVulnerability first disclosed.
2. 16-04-2025
   Last modifiedVulnerability information updated.

Description

ARM mbed-ualloc memory library version 1.3.0 is vulnerable to integer wrap-around in function mbed_krbs, which can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

• 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.