CVE-2007-5207 in guilt
Summary
by MITRE
guilt 0.27 allows local users to overwrite arbitrary files via a symlink attack on a guilt.log.[PID] temporary file.
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Analysis
by VulDB Data Team • 09/09/2018
The vulnerability identified as CVE-2007-5207 affects guilt version 0.27, a tool used for managing git repositories with a focus on maintaining clean commit histories through interactive rebase operations. This security flaw represents a classic symlink attack scenario that exploits improper temporary file handling within the application's logging mechanism. The vulnerability occurs when guilt creates temporary log files with predictable naming patterns that include process identifiers, making them susceptible to manipulation by local attackers who can establish symbolic links to target sensitive files.
The technical implementation of this vulnerability stems from the application's failure to properly validate or secure temporary file creation processes. When guilt executes operations that require logging, it generates temporary files following the naming convention guilt.log.PID where PID represents the process identifier. Local attackers can exploit this predictable naming scheme by creating symbolic links with the same names before guilt attempts to write to them, effectively causing the application to write data to arbitrary locations on the filesystem. This type of attack falls under the category of time-of-check to time-of-use vulnerabilities, where the application checks for file existence and permissions before creating or writing to files, but the actual file operations occur after potential manipulation has occurred.
The operational impact of this vulnerability extends beyond simple file overwriting, as it can enable attackers to modify critical system files, configuration data, or even inject malicious content into the application's logging infrastructure. An attacker with local access can leverage this vulnerability to escalate privileges, modify application behavior, or potentially establish persistence mechanisms within the system. The vulnerability is particularly concerning because it operates at the local user level, meaning that any user with access to the system can potentially exploit it, and the damage can be significant depending on the privileges of the user running the guilt application. This aligns with CWE-367 weakness classification which addresses Time-of-Check to Time-of-Use race conditions, and represents a clear violation of the principle of least privilege.
Mitigation strategies for this vulnerability should focus on implementing proper temporary file handling practices that prevent symlink attacks. The most effective approach involves using secure temporary file creation methods that ensure atomic operations and proper file permissions, such as creating temporary files with unique, unpredictable names and using system calls that prevent symbolic link resolution during file creation. Additionally, the application should validate that temporary files are created with appropriate permissions and that they are not subject to manipulation by other users. From an operational perspective, system administrators should ensure that the guilt application runs with minimal necessary privileges and that the system maintains proper file system permissions. This vulnerability also demonstrates the importance of following secure coding practices outlined in the OWASP Secure Coding Guidelines, particularly those addressing temporary file handling and race condition prevention. The ATT&CK framework categorizes this type of vulnerability under privilege escalation techniques, specifically focusing on the use of local tools to gain elevated system access through improper file handling mechanisms.