CVE-2004-0906 in Firefox
Summary
by MITRE
The XPInstall installer in Mozilla Firefox before the Preview Release, Mozilla before 1.7.3, and Thunderbird before 0.8 sets insecure permissions for certain installed files within xpi packages, which could allow local users to overwrite arbitrary files or execute arbitrary code.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability identified as CVE-2004-0906 represents a critical security flaw in the XPInstall installer component of Mozilla Firefox, Mozilla Suite, and Thunderbird applications. This issue stems from improper file permission handling during the installation of xpi packages, which are the extension and add-on packages used by these applications. The vulnerability affects versions prior to Firefox Preview Release, Mozilla 1.7.3, and Thunderbird 0.8, creating a window of exposure for users running these older software versions.
The technical flaw manifests in the XPInstall installer's failure to properly secure file permissions when extracting and installing components from xpi packages. Specifically, the installer creates certain files with overly permissive access controls that allow local users to modify or replace critical system files. This insecure permission setting creates a privilege escalation vector where malicious actors can leverage the installer's behavior to gain elevated system access. The vulnerability operates at the file system level, exploiting the trust model that exists between the installation process and the underlying operating system's permission mechanisms. According to CWE-276, this represents a classic improper file permissions vulnerability where the system fails to establish appropriate access controls for installed components.
The operational impact of this vulnerability extends beyond simple file modification capabilities to potentially enable arbitrary code execution. Local users who can influence the installation process or have access to systems running vulnerable software can exploit this weakness to overwrite critical system files with malicious content. This creates opportunities for privilege escalation attacks where attackers can gain elevated privileges on the affected systems. The vulnerability is particularly dangerous because it operates within the legitimate installation framework of the applications, making detection more challenging for security monitoring systems. Attackers could craft malicious xpi packages that, when installed, would modify system binaries or configuration files to establish persistent access or execute unauthorized code.
Mitigation strategies for CVE-2004-0906 primarily focus on immediate software updates to patched versions of the affected applications. Users should upgrade to Mozilla Firefox 1.7.3, Mozilla Suite 1.7.3, and Thunderbird 0.8 or later versions where the installer's permission handling has been corrected. System administrators should implement strict access controls and monitoring for file system changes, particularly in directories where application extensions are installed. The vulnerability aligns with ATT&CK technique T1059.001 for execution through command-line interfaces and T1068 for privilege escalation, making it a significant concern for enterprise security teams. Additional protective measures include implementing application whitelisting policies that restrict which xpi packages can be installed and conducting regular security audits of installed extensions to identify potential malicious modifications. Organizations should also consider deploying endpoint protection solutions that can detect and prevent unauthorized file modifications during installation processes.