Privilege escalation in Thunderbird Updater
Vulnerability Description
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.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
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Credits & Attribution
The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:
- Dong-uk Kim (@justlikebono)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1917536
- https://www.mozilla.org/security/advisories/mfsa2025-28/
- https://www.mozilla.org/security/advisories/mfsa2025-29/
- https://www.mozilla.org/security/advisories/mfsa2025-30/
- https://www.mozilla.org/security/advisories/mfsa2025-31/
- https://www.mozilla.org/security/advisories/mfsa2025-32/
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Timeline
CVSS Vectors
Weaknesses (CWE)
No CWE data available
MITRE ATT&CK TTPs
No associated TTPs found for this vulnerability.