CVE-2008-4942 in audiolink
Summary
by MITRE
audiolink in audiolink 0.05 allows local users to overwrite arbitrary files via a symlink attack on the (1) /tmp/audiolink.db.tmp and (2) /tmp/audiolink.tb.tmp temporary files.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/13/2018
The vulnerability described in CVE-2008-4942 represents a critical security flaw in the audiolink software version 0.05 that enables local privilege escalation through improper temporary file handling. This issue falls under the category of insecure temporary file creation, specifically manifesting as a race condition vulnerability that can be exploited by malicious local users to gain unauthorized access to system resources. The vulnerability stems from the application's failure to properly validate or secure temporary files during their creation process, creating an exploitable window where adversaries can manipulate file system permissions and content.
The technical implementation of this vulnerability involves the audiolink application creating temporary files with predictable names in the /tmp directory without adequate security measures. Specifically, the application creates two temporary files named /tmp/audiolink.db.tmp and /tmp/audiolink.tb.tmp which are susceptible to symbolic link attacks. When a local attacker creates symbolic links with these exact names before the audiolink application attempts to write to them, the application will write data to the attacker-controlled target file instead of the intended temporary file. This fundamental flaw in temporary file management creates a privilege escalation vector where unprivileged users can overwrite arbitrary files with content controlled by the attacker.
The operational impact of this vulnerability extends beyond simple file overwriting capabilities, as it provides attackers with the potential to modify critical system files, configuration data, or even executable components that could lead to privilege escalation. The vulnerability is particularly concerning because it operates at the local user level, meaning that any user with access to the system can exploit it without requiring external network access or complex attack vectors. This makes it an attractive target for attackers seeking to establish persistent access or escalate privileges within compromised systems, particularly in multi-user environments where local users might have varying levels of system access.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-377: Insecure Temporary Files and CWE-378: Poorly Specified Temporary File Permissions, both of which are categorized under the broader weakness in software design that leads to insecure file handling practices. The attack pattern follows the established techniques described in the MITRE ATT&CK framework under T1059.007 for Command and Scripting Interpreter: PowerShell and T1548.001 for Abuse of Functionality, where attackers leverage legitimate system utilities to manipulate temporary file creation processes. The vulnerability also demonstrates characteristics of T1078.004 for Valid Accounts: Default Accounts and T1566.001 for Phishing: Spearphishing Attachment, as it can be combined with social engineering techniques to gain initial access to systems where local users can create symbolic links.
Effective mitigations for this vulnerability require immediate implementation of proper temporary file handling practices, including the use of secure temporary file creation functions that prevent symbolic link attacks, proper file permission management, and validation of temporary file paths. System administrators should ensure that applications create temporary files with unpredictable names and implement proper file ownership controls that prevent unauthorized modification. The audiolink application should be updated to use atomic file creation methods that avoid race conditions, and the system should enforce proper file permissions on the /tmp directory to prevent unauthorized symbolic link creation. Additionally, regular security auditing of temporary file usage patterns and monitoring for suspicious file creation activities can help detect exploitation attempts. Organizations should also consider implementing privilege separation techniques and ensuring that applications run with minimal required privileges to limit the potential impact of such vulnerabilities. The vulnerability underscores the importance of secure coding practices and proper input validation in preventing exploitation of temporary file handling flaws that can lead to system compromise.