CVE-2004-0907 in Mozilla
Summary
by MITRE
The Linux install .tar.gz archives for Mozilla Firefox before the Preview Release, Mozilla before 1.7.3, and Thunderbird before 0.8, create certain files with insecure permissions, which could allow local users to overwrite those files and execute arbitrary code.
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Analysis
by VulDB Data Team • 05/25/2019
This vulnerability involves a critical security flaw in the installation process of Mozilla Firefox and Thunderbird versions prior to their respective secure releases. The issue stems from the improper handling of file permissions during the decompression and installation of .tar.gz archives on Linux systems. When these applications were installed, certain configuration and executable files were created with overly permissive access controls, specifically allowing world-writable permissions that should have been restricted to the installing user or system administrators only. This fundamental flaw in the installation routine creates a persistent security risk that can be exploited by local attackers to gain elevated privileges and execute malicious code with the privileges of the installed application or system processes.
The technical implementation of this vulnerability occurs during the unpacking phase of the installation process where the tar.gz archives contain files that are extracted without proper permission enforcement. The insecure file permissions typically involve configuration files, plugin directories, or executable components that are created with chmod 777 or similar overly permissive settings. This allows any local user on the system to modify or replace these critical files, potentially injecting malicious code that will execute with the privileges of the targeted application. The vulnerability is particularly dangerous because it leverages the legitimate installation process to create a backdoor that persists across system reboots and application restarts.
From an operational perspective, this vulnerability creates a significant attack surface for local privilege escalation attacks. The attack vector requires only local system access, making it particularly dangerous in multi-user environments where users might not have administrative privileges. Attackers can exploit this by replacing legitimate files with malicious counterparts, potentially gaining access to sensitive data, modifying system configurations, or establishing persistent access points. The impact extends beyond the immediate application to potentially compromise the entire system if the installed application has elevated privileges or if the malicious files are executed in contexts with broader system access. This vulnerability directly aligns with CWE-732: Incorrect Permission Assignment for Critical Resource, which specifically addresses the assignment of incorrect permissions to security-critical resources.
The exploitation of this vulnerability requires minimal technical skill and can be automated, making it particularly dangerous in environments where multiple users have access to the system. The attack pattern follows typical privilege escalation methodologies and can be mapped to ATT&CK technique T1068: Exploitation for Privilege Escalation, where local users leverage insecure file permissions to gain elevated system privileges. Security professionals should note that this vulnerability was particularly concerning because it affected widely deployed applications and could be exploited without requiring network access or specialized knowledge of the target system. The remediation involves proper file permission handling during installation processes and ensuring that system administrators validate installation integrity before deployment in production environments. Organizations should implement proper file permission auditing and regularly verify that installed applications maintain appropriate access controls to prevent exploitation of similar insecure installation practices in other software packages.