By crafting a malformed file name for an attachment in a multipart message, an attacker can trick Thunderbird into including a directory listing of /tmp when the message is forwarded or edited as a new message. This vulnerability could allow attackers to disclose sensitive information from the victim's system. This vulnerability is not limited to Linux; similar behavior has been observed on Windows as well. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
| Link | Tags |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1956379 | permissions required |
| https://www.mozilla.org/security/advisories/mfsa2025-26/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-27/ | vendor advisory |