CVE-2021-29972

A use-after-free vulnerability was found via testing, and traced to an out-of-date Cairo library. Updating the library resolved the issue, and may have remediated other, unknown security vulnerabilities as well. This vulnerability affects Firefox < 90.

Weakness

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1696816
• https://security.gentoo.org/glsa/202202-03
• https://www.mozilla.org/security/advisories/mfsa2021-28/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1696816
• https://security.gentoo.org/glsa/202202-03
• https://www.mozilla.org/security/advisories/mfsa2021-28/