CVE-2020-6807

When a device was changed while a stream was about to be destroyed, the stream-reinit task may have been executed after the stream was destroyed, causing a use-after-free and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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=1614971
• https://usn.ubuntu.com/4328-1/
• https://usn.ubuntu.com/4335-1/
• https://www.mozilla.org/security/advisories/mfsa2020-08/
• https://www.mozilla.org/security/advisories/mfsa2020-09/
• https://www.mozilla.org/security/advisories/mfsa2020-10/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1614971
• https://usn.ubuntu.com/4328-1/
• https://usn.ubuntu.com/4335-1/
• https://www.mozilla.org/security/advisories/mfsa2020-08/
• https://www.mozilla.org/security/advisories/mfsa2020-09/
• https://www.mozilla.org/security/advisories/mfsa2020-10/