CVE-2008-2802 in Firefox
Summary
by MITRE
Mozilla Firefox before 2.0.0.15, Thunderbird 2.0.0.14 and earlier, and SeaMonkey before 1.1.10 allow remote attackers to execute arbitrary code via an XUL document that includes a script from a chrome: URI that points to a fastload file, related to this file s "privilege level."
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Analysis
by VulDB Data Team • 08/12/2019
This vulnerability represents a critical privilege escalation flaw in Mozilla Firefox, Thunderbird, and SeaMonkey browsers that stems from improper handling of chrome URIs within XUL documents. The vulnerability exists in versions prior to the specified patches, where the browser fails to adequately validate the privilege level of scripts loaded from chrome: URIs that reference fastload files. The core technical issue involves the browser's failure to properly enforce security boundaries between chrome-level privileges and user-level content, allowing malicious actors to escalate privileges through carefully crafted XUL documents that reference chrome resources.
The flaw operates through a specific attack vector involving XUL (XML User Interface Language) documents that contain embedded scripts pointing to chrome: URIs. These chrome: URIs reference fastload files which are precompiled JavaScript resources that normally operate at elevated privilege levels within the browser's chrome context. When a malicious XUL document loads such a script, the browser incorrectly grants it the elevated privileges of the chrome environment rather than maintaining proper privilege separation. This creates a path for remote code execution as attackers can craft documents that leverage these elevated privileges to perform actions that would normally be restricted to the browser's internal components.
The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code on vulnerable systems with the privileges of the browser process itself. This means that successful exploitation could result in complete system compromise, as the attacker gains access to all browser capabilities including the ability to read and write files, make network connections, and potentially escalate to full system privileges depending on the operating environment. The vulnerability is particularly dangerous because it can be triggered through web pages or email content, making it highly exploitable in real-world scenarios without requiring user interaction beyond visiting a malicious site or opening a compromised email.
Mitigation strategies for this vulnerability involve updating to the patched versions of the affected software products, specifically Firefox 2.0.0.15, Thunderbird 2.0.0.14, and SeaMonkey 1.1.10. Organizations should also implement network-level protections such as content filtering and sandboxing measures to limit the impact of potential exploitation attempts. The vulnerability aligns with CWE-264, which addresses permissions, privileges, and access control issues, and maps to ATT&CK technique T1059.007 for execution through JavaScript and T1068 for privilege escalation. Security teams should also consider implementing browser hardening measures and monitoring for suspicious XUL document loading patterns to detect potential exploitation attempts.