Privilege Escalation Vulnerability in Mozilla Firefox and Thunderbird

CVE-2025-2817

What is CVE-2025-2817?

CVE-2025-2817 is a privilege escalation vulnerability found in the Mozilla Firefox and Thunderbird software. Both products are widely used for web browsing and email communication, respectively. This vulnerability arises from the update mechanism in Firefox, which improperly permits a medium-integrity user process to manipulate SYSTEM-level updates. If exploited, it could allow an attacker to gain elevated privileges, thereby compromising security and operational integrity within an organization.

Technical Details

The vulnerability is related to the way Mozilla Firefox's update mechanism handles file-locking behaviors. An attacker can leverage this weakness to inject code into a user-privileged process. By doing so, they can bypass essential access controls, gaining the ability to perform SYSTEM-level file operations in locations that a non-privileged user should not access. This flaw affects several versions of Firefox and Thunderbird, including Firefox versions below 138 and Thunderbird versions below 138.

Potential Impact of CVE-2025-2817

1. Privilege Escalation: Attackers could exploit this vulnerability to elevate their privileges within the system, potentially gaining access to sensitive data and administrative functionalities that should have been restricted.

2. System Compromise: By executing SYSTEM-level operations, an attacker could effectively take control of the affected systems, leading to further unauthorized actions that may include data theft or manipulation.

3. Security Breaches: The exploitation of this vulnerability could lead to significant security incidents, potentially exposing organizations to data breaches, legal repercussions, and reputational damage.

References