An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.
| Link | Tags |
|---|---|
| https://www.mozilla.org/security/advisories/mfsa2019-35/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2019-33/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2019-34/ | vendor advisory |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1577953 | issue tracking permissions required |
| https://security.gentoo.org/glsa/202003-10 | third party advisory vendor advisory |
| https://usn.ubuntu.com/4335-1/ | third party advisory vendor advisory |