CVE-2002-0137 in CDRDAO
Summary
by MITRE
CDRDAO 1.1.4 and 1.1.5 allows local users to overwrite arbitrary files via a symlink attack on the $HOME/.cdrdao configuration file.
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Analysis
by VulDB Data Team • 11/15/2024
The vulnerability identified as CVE-2002-0137 affects CDRDAO versions 1.1.4 and 1.1.5, representing a classic symlink attack or race condition issue that enables local privilege escalation through file overwrite operations. This flaw resides in the application's handling of configuration files within the user's home directory, specifically the $HOME/.cdrdao file which serves as the primary configuration storage for the CD recording tool. The vulnerability stems from insufficient input validation and improper file access controls during the configuration file creation process, allowing malicious actors to manipulate the system's file structure through symbolic link manipulation.
The technical implementation of this vulnerability exploits the predictable naming convention of the configuration file and the lack of proper file existence checks before file operations. When CDRDAO initializes or updates its configuration file, it does not verify whether the target file is a symbolic link or if it already exists with write permissions. This creates a window of opportunity where a local attacker can create a symbolic link with the name of the configuration file in the user's home directory, pointing to a critical system file or another location where they can gain write access. The flaw is particularly dangerous because it allows attackers to overwrite files with arbitrary content, potentially leading to privilege escalation or system compromise.
The operational impact of this vulnerability extends beyond simple file overwrite capabilities, as it can be leveraged to escalate privileges and compromise system integrity. Attackers can use this technique to replace system configuration files, executable binaries, or other critical resources with malicious versions, effectively creating persistent backdoors or gaining elevated privileges. The vulnerability affects all local users who execute CDRDAO with write permissions in their home directories, making it particularly concerning in multi-user environments where users might have varying privilege levels. According to CWE classification, this vulnerability maps to CWE-59, which describes improper handling of a symbolic link, and CWE-276, which addresses incorrect permissions for a resource.
Mitigation strategies for CVE-2002-0137 should focus on immediate patching of affected CDRDAO versions, with the implementation of proper file access controls and validation mechanisms. System administrators should ensure that all users have proper file permissions and that the configuration file creation process includes checks for symbolic links and existing file states. The solution involves modifying the application to either create configuration files with exclusive access flags, implement proper atomic file operations, or verify file integrity before writing operations. Additionally, implementing the principle of least privilege and restricting write access to user home directories can significantly reduce the attack surface. From an ATT&CK perspective, this vulnerability aligns with techniques such as T1068 for local privilege escalation and T1546 for persistence mechanisms, making it a critical concern for security monitoring and incident response teams. Organizations should also consider implementing file integrity monitoring solutions to detect unauthorized configuration file modifications and establish proper security awareness training for system administrators and users.