When recursing through graphical layers while scrolling, an iterator may have become invalid, resulting in a potential use-after-free. This occurs because the function APZCTreeManager::ComputeClippedCompositionBounds did not follow iterator invalidation rules. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://www.mozilla.org/security/advisories/mfsa2020-43/ | release notes vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2020-44/ | release notes vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2020-42/ | release notes vendor advisory |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1660211 | vendor advisory issue tracking permissions required |
| https://www.debian.org/security/2020/dsa-4770 | third party advisory vendor advisory |
| https://lists.debian.org/debian-lts-announce/2020/10/msg00020.html | third party advisory mailing list |
| https://security.gentoo.org/glsa/202010-02 | third party advisory vendor advisory |
| http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00074.html | vendor advisory broken link mailing list third party advisory |
| http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00077.html | vendor advisory broken link mailing list third party advisory |