The Firefox updater created a directory writable by non-privileged users. When uninstalling Firefox, any files in that directory would be recursively deleted with the permissions of the uninstalling user account. This could be combined with creation of a junction (a form of symbolic link) to allow arbitrary file deletion controlled by the non-privileged user. *This bug only affects Firefox on Windows. Other operating systems are unaffected.* This vulnerability affects Firefox < 116, Firefox ESR < 115.1, and Thunderbird < 115.1.
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
| Link | Tags |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1824420 | issue tracking permissions required |
| https://www.mozilla.org/security/advisories/mfsa2023-29/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2023-31/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2023-33/ |