Path Traversal in Mozilla Firefox
CVE-2025-2817
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.006 (43.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Mozilla Firefox — versions 115.23, 128.10, 138
- Mozilla Thunderbird — versions 128.10, 138
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@mozilla.org (Permissions Required)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-2817?
- CVE-2025-2817 is a high-severity vulnerability in Mozilla Firefox, classified under Path Traversal. CVSS score: 8.8/10. Published 2025-04-29.
- How severe is CVE-2025-2817?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2025-2817 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.