CVE-2008-4965 in liguidsoap
Summary
by MITRE
liguidsoap.py in liguidsoap 0.3.8.1+2 allows local users to overwrite arbitrary files via a symlink attack on (1) /tmp/liguidsoap.liq, (2) /tmp/lig.#####.log, and (3) /tmp/emission.ogg temporary files.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/04/2017
The vulnerability identified as CVE-2008-4965 affects liquidsoap 0.3.8.1+2, a popular streaming media server software used for broadcasting audio content over the internet. This issue represents a classic symlink attack vulnerability that exploits insecure temporary file handling within the application's operation. The vulnerability stems from the application's failure to properly validate file paths when creating temporary files, creating opportunities for local attackers to manipulate the system's file structure through symbolic link manipulation.
The technical flaw manifests through three specific temporary file locations that liquidsoap creates during operation: /tmp/liguidsoap.liq, /tmp/lig.#####.log, and /tmp/emission.ogg. These temporary files are created with predictable naming patterns and are written to the /tmp directory without proper security checks. When an attacker creates symbolic links with these exact names in the /tmp directory before the legitimate application attempts to create them, the application will write data to the attacker-controlled target files instead of the intended temporary locations. This creates a privilege escalation scenario where local users can overwrite arbitrary files on the system with data controlled by the attacker, potentially leading to system compromise or data corruption.
The operational impact of this vulnerability extends beyond simple file overwrites as it can be exploited to gain elevated privileges or disrupt system operations. Attackers can leverage this vulnerability to overwrite critical system files, configuration files, or even binaries that the liquidsoap service might execute with elevated privileges. The vulnerability is particularly concerning in environments where liquidsoap runs with higher privileges or where the application is used in broadcast environments where system stability is paramount. This type of attack falls under the category of insecure temporary file handling as defined by CWE-377, which specifically addresses the creation of temporary files with insecure permissions or predictable names.
The attack vector requires local system access and relies on the attacker's ability to create symbolic links in the /tmp directory before the legitimate application creates its temporary files. This makes the vulnerability particularly dangerous in multi-user environments where attackers might have limited access but can still manipulate temporary file creation order. According to ATT&CK framework, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1548 (Abuse Elevation Control Mechanism) as attackers can potentially escalate privileges through file overwrites. The vulnerability also relates to T1078 (Valid Accounts) since the attack requires local access to the system, and T1213 (Data from Information Repositories) as the compromised system could potentially expose sensitive broadcast data.
Mitigation strategies for CVE-2008-4965 should focus on implementing proper temporary file handling mechanisms that prevent symbolic link attacks. The most effective approach involves using secure temporary file creation methods that ensure file integrity and prevent attackers from manipulating the file creation process. This includes implementing proper file permission controls, using secure temporary file creation functions that atomically create files with exclusive access, and avoiding predictable temporary file names. Organizations should also consider implementing file system monitoring to detect unauthorized symbolic link creation in temporary directories. Additionally, upgrading to a patched version of liquidsoap that properly handles temporary file creation would provide the most comprehensive solution. System administrators should also consider implementing mandatory access controls and restricting write permissions to the /tmp directory to limit the potential impact of such attacks. The vulnerability demonstrates the importance of following secure coding practices and proper input validation when handling temporary file operations, as highlighted by CWE-276 which addresses improper file permissions and access control issues.