CVE-2012-1093 in x11-common
Summary
by MITRE
The init script in the Debian x11-common package before 1:7.6+12 is vulnerable to a symlink attack that can lead to a privilege escalation during package installation.
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Analysis
by VulDB Data Team • 04/22/2023
The vulnerability identified as CVE-2012-1093 resides within the init script of the Debian x11-common package, specifically affecting versions prior to 1:7.6+12. This issue represents a classic symlink attack vector that exploits the insecure handling of temporary files during package installation processes. The flaw allows malicious actors to manipulate symbolic links in a way that can result in unauthorized privilege escalation, making it a significant concern for system security. The vulnerability is particularly dangerous because it operates during the package installation phase, when the system is already in a state of elevated privilege, providing attackers with an ideal opportunity to gain higher-level access rights.
The technical implementation of this vulnerability stems from improper handling of symbolic links within the package installation scripts. When the x11-common package installs or updates, it creates temporary files and directories that are susceptible to manipulation through symlink attacks. The init script fails to properly validate or sanitize the symbolic link references, allowing an attacker to create malicious symbolic links that point to critical system files or directories. This flaw directly maps to CWE-377, which addresses insecure temporary file handling, and CWE-271, which covers privilege escalation through improper access control. The vulnerability demonstrates a clear breakdown in the principle of least privilege, where the installation process does not adequately protect against symlink-based attacks that could compromise the integrity of the system.
The operational impact of CVE-2012-1093 extends beyond simple privilege escalation, as it can enable attackers to gain root access to affected systems. During package installation, the system typically runs with elevated privileges to ensure proper system modifications, but this elevated state creates an attack surface that the symlink vulnerability exploits. An attacker could potentially place malicious symbolic links in locations where the installation script expects to find temporary files, causing the system to execute code with higher privileges than intended. This vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of system weaknesses, and T1548.001, which addresses privilege escalation through legitimate system tools. The impact is particularly severe in environments where automated package management systems are in use, as these systems often run with elevated privileges and may be more susceptible to such attacks.
Mitigation strategies for this vulnerability require immediate patching of the affected x11-common package to version 1:7.6+12 or later, which contains the necessary fixes to prevent symlink attacks during installation. System administrators should also implement proper file system permissions and ensure that temporary directories used during package installation are properly secured against symbolic link manipulation. Additional protective measures include monitoring package installation processes for suspicious activity and implementing proper access controls on system directories that are referenced during installation. Organizations should also consider implementing automated vulnerability scanning tools that can detect and alert on similar symlink attack patterns in other system components. The remediation process should include comprehensive testing to ensure that the patch does not introduce regressions in system functionality, while also verifying that the fix properly addresses the underlying symlink handling issues. This vulnerability serves as a reminder of the critical importance of secure coding practices in system-level scripts and the need for regular security assessments of package management processes.