CVE-2005-2353 in Thunderbird
Summary
by MITRE
run-mozilla.sh in Thunderbird, with debugging enabled, allows local users to create or overwrite arbitrary files via a symlink attack on temporary files.
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Analysis
by VulDB Data Team • 07/11/2019
The vulnerability described in CVE-2005-2353 affects the run-mozilla.sh script within Mozilla Thunderbird email client when debugging features are enabled. This represents a classic symlink attack scenario that exploits insecure temporary file handling mechanisms. The flaw exists in the way the script manages temporary files during the debugging process, creating opportunities for local attackers to manipulate the filesystem through symbolic link manipulation. The vulnerability specifically targets the execution environment where debugging capabilities are active, making it particularly relevant in development or testing scenarios where these features might be enabled.
The technical implementation of this vulnerability stems from the insecure creation of temporary files without proper validation of symbolic links. When debugging is enabled, the run-mozilla.sh script creates temporary files that are subsequently used in the execution flow. An attacker can exploit this by pre-creating symbolic links with the same names as expected temporary files, causing the script to write data to unintended locations. This type of attack falls under the category of time-of-check to time-of-use race conditions and represents a well-documented weakness in Unix-like systems where temporary file operations are not properly secured. The vulnerability is classified as a privilege escalation issue since it allows local users to potentially overwrite files with elevated privileges that the script may possess.
The operational impact of this vulnerability extends beyond simple file manipulation as it can lead to more serious security consequences. An attacker could use this technique to overwrite critical system files, configuration files, or even executable binaries that the debugging process might access. The attack vector is particularly dangerous in environments where Thunderbird is run with elevated privileges or where the debugging features are enabled in production environments. This vulnerability can be exploited to gain persistent access to systems or to disrupt normal operations by corrupting essential files. The attack requires local access but can be particularly damaging when combined with other exploitation techniques or when the target system has debugging enabled inappropriately.
Mitigation strategies for this vulnerability should focus on proper temporary file handling practices and privilege management. The most effective approach involves implementing secure temporary file creation mechanisms that prevent symbolic link attacks, such as using file descriptors or creating temporary files with unique names and proper permissions. System administrators should disable debugging features in production environments where they are not required, as this eliminates the attack surface entirely. The implementation of proper file permission controls and the use of secure coding practices for temporary file creation aligns with security standards such as those outlined in the CWE-377 weakness category for insecure temporary files. Additionally, this vulnerability demonstrates the importance of following the principle of least privilege and implementing proper access controls as recommended by various cybersecurity frameworks including those referenced in the MITRE ATT&CK matrix for privilege escalation techniques. Organizations should also implement regular security assessments to identify and remediate similar vulnerabilities in other applications that may exhibit similar insecure temporary file handling patterns.