CVE-2019-9796: mozilla firefox Use After Free

Vulnerability summary

CVE-2019-9796 is a critical (CVSS 9.8) Use After Free vulnerability in mozilla firefox. EPSS estimates a 2.06% chance of exploitation in the next 30 days, higher than 81% of scored vulnerabilities.

Timeline

1. 26-04-2019
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

A use-after-free vulnerability can occur when the SMIL animation controller incorrectly registers with the refresh driver twice when only a single registration is expected. When a registration is later freed with the removal of the animation controller element, the refresh driver incorrectly leaves a dangling pointer to the driver's observer array. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

• 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.