CVE-2021-24037: facebook hermes Use After Free

Vulnerability summary

CVE-2021-24037 is a critical (CVSS 9.8) Use After Free vulnerability in facebook hermes. EPSS estimates a 1.80% chance of exploitation in the next 30 days, higher than 78.1% of scored vulnerabilities.

Timeline

1. 15-06-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

Description

A use after free in hermes, while emitting certain error messages, prior to commit d86e185e485b6330216dee8e854455c694e3a36e allows attackers to potentially execute arbitrary code via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.