CVE-2009-4454 in VideoCache
Summary
by MITRE
vccleaner in VideoCache 1.9.2 allows local users with Squid proxy user privileges to overwrite arbitrary files via a symlink attack on /var/log/videocache/vccleaner.log.
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Analysis
by VulDB Data Team • 12/21/2024
The vulnerability identified as CVE-2009-4454 represents a critical file system security flaw within the VideoCache 1.9.2 software package, specifically affecting the vccleaner component. This issue manifests as a symlink attack vulnerability that enables local users with Squid proxy user privileges to manipulate the file system in unauthorized ways. The vulnerability occurs due to insufficient validation of symbolic link references within the application's logging mechanism, creating a path traversal scenario that can be exploited by malicious actors with limited system access. The attack vector specifically targets the /var/log/videocache/vccleaner.log file location, which serves as the primary logging destination for the application's cleanup operations.
The technical implementation of this vulnerability stems from the application's failure to properly validate or sanitize symbolic link references when creating or updating log files. When vccleaner executes its operations, it creates or modifies log files without adequately checking whether the target path contains symbolic links that could be manipulated by an attacker. This flaw aligns with CWE-59, which addresses improper link resolution without limit checks, and specifically relates to CWE-377, concerning insecure temporary file creation. The vulnerability exists because the software does not implement proper atomic file creation mechanisms or symbolic link verification procedures that would prevent attackers from redirecting file operations to arbitrary locations within the file system.
From an operational perspective, this vulnerability presents a significant risk to systems running VideoCache software, particularly in environments where Squid proxy services are deployed with user privileges. Local users who have access to the Squid proxy functionality can leverage this weakness to overwrite arbitrary files on the system, potentially leading to privilege escalation, data corruption, or complete system compromise. The impact extends beyond simple file overwrite operations, as attackers could redirect logging to critical system files, overwrite configuration files, or even inject malicious content into system components. This vulnerability operates under the ATT&CK framework's technique T1059, specifically targeting the execution of malicious code through legitimate system processes, and represents a path to privilege escalation via insecure file handling practices.
The exploitation of this vulnerability requires minimal privileges and can be executed through a carefully crafted symlink attack that manipulates the logging process. Attackers would create symbolic links pointing to sensitive system files within the targeted directory structure, then trigger the vccleaner process to overwrite these links with malicious content. The attack is particularly concerning because it can be executed without requiring administrative privileges, making it accessible to users who would normally have limited system access. Organizations should consider implementing additional security controls such as file system permissions, regular log file monitoring, and proper symbolic link validation mechanisms. Mitigation strategies include updating to patched versions of VideoCache, implementing proper file system access controls, and monitoring for unauthorized symbolic link creation in sensitive directories. The vulnerability highlights the importance of secure coding practices and proper input validation in system components that handle file operations, particularly in logging and cleanup utilities.