Improper locking in Mozilla Firefox and Firefox ESR - CVE-2025-2817

Vulnerability identifier: #VU108044

CSH Severity: Low

CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

CVE-ID: CVE-2025-2817

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

Affected software:
Mozilla Firefox
Firefox ESR
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP3
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Workstation Extension 15
Anolis OS
SUSE Enterprise Storage
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Slackware Linux
SUSE Package Hub 15
Desktop Applications Module
openSUSE Leap
openEuler
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
mozilla-firefox
mozilla-thunderbird
firefox-debugsource
firefox
firefox-debuginfo
firefox (Red Hat package)
thunderbird (Red Hat package)
thunderbird
MozillaFirefox-debugsource
MozillaFirefox
MozillaFirefox-translations-common
MozillaFirefox-debuginfo
MozillaFirefox-devel
MozillaThunderbird-debuginfo
MozillaThunderbird-translations-common
MozillaThunderbird
MozillaThunderbird-debugsource
MozillaThunderbird-translations-other
MozillaFirefox-branding-upstream
MozillaFirefox-translations-other
thunderbird-debuginfo
thunderbird-debugsource
thunderbird-librnp-rnp
thunderbird-wayland
Mozilla Thunderbird

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper locking mechanism in Firefox Updater. A medium-integrity user process can  interfere with the SYSTEM-level updater by manipulating the file-locking behavior by injecting code into the user-privileged process. A local user or malicious software installed on the system can bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation.

Install updates from vendor's website.

• https://www.mozilla.org/en-US/security/advisories/mfsa2025-30/
• https://www.mozilla.org/en-US/security/advisories/mfsa2025-28/
• https://www.mozilla.org/en-US/security/advisories/mfsa2025-29/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1917536