CVE-2013-1712 in Firefox
Summary
by MITRE
Multiple untrusted search path vulnerabilities in updater.exe in Mozilla Updater in Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird before 17.0.8, and Thunderbird ESR 17.x before 17.0.8 on Windows 7, Windows Server 2008 R2, Windows 8, and Windows Server 2012 allow local users to gain privileges via a Trojan horse DLL in (1) the update directory or (2) the current working directory.
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Analysis
by VulDB Data Team • 05/21/2021
The vulnerability described in CVE-2013-1712 represents a critical privilege escalation issue affecting Mozilla's updater component across multiple browser and email applications. This flaw resides in the updater.exe executable that manages software updates for Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR versions prior to the specified patches. The vulnerability specifically targets Windows operating systems including Windows 7, Windows Server 2008 R2, Windows 8, and Windows Server 2012, creating a significant attack surface for local adversaries seeking to elevate their privileges.
The technical root cause of this vulnerability stems from improper handling of dynamic library loading within the updater.exe process. When the updater executes, it searches for required DLL libraries using an untrusted search path mechanism that does not properly validate or restrict the locations from which these dependencies can be loaded. This behavior creates a classic DLL hijacking scenario where malicious actors can place specially crafted Trojan horse DLL files in strategic locations within the update directory or current working directory. The updater.exe process, running with elevated privileges during the update process, will load these malicious libraries instead of the legitimate system DLLs, allowing attackers to execute arbitrary code with the privileges of the updater process.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it provides attackers with a reliable method to gain elevated system access without requiring user interaction or complex exploitation techniques. Attackers can leverage this vulnerability by simply placing a malicious DLL file in the appropriate directory, making the attack vector particularly dangerous in environments where users may have write access to update directories or where the current working directory is not properly controlled. The vulnerability affects not only individual user systems but also enterprise environments where automated update processes may be running with elevated privileges, potentially enabling attackers to establish persistent access to critical systems.
This vulnerability aligns with CWE-427 Uncontrolled Search Path Elements, which specifically addresses the risk of programs loading libraries from untrusted directories. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under T1068, Local Privilege Escalation, and T1546, Event Triggered Execution, as the malicious DLL execution occurs during the normal update process. Organizations should immediately implement mitigations including updating to patched versions of the affected software, implementing strict directory permissions to prevent unauthorized DLL placement, and monitoring for suspicious file creation in update directories. The vulnerability also highlights the importance of secure coding practices in update mechanisms and the necessity of implementing proper DLL loading security measures such as specifying full paths for library loading or using Windows' DEP and ASLR protections to mitigate similar attack vectors.