CVE-2010-3387 in vdr
Summary
by MITRE
** DISPUTED ** vdrleaktest in Video Disk Recorder (VDR) 1.6.0 places a zero-length directory name in the LD_LIBRARY_PATH, which allows local users to gain privileges via a Trojan horse shared library in the current working directory. NOTE: a third party disputes this issue because the script erroneously uses a semicolon in a context where a colon was intended.
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Analysis
by VulDB Data Team • 08/07/2024
The vulnerability identified as CVE-2010-3387 pertains to Video Disk Recorder version 1.6.0 and involves a critical flaw in how the vdrleaktest utility handles library path configuration. This issue manifests when the utility places a zero-length directory name within the LD_LIBRARY_PATH environment variable, creating a security exposure that could be exploited by local attackers. The flaw represents a classic privilege escalation vector where malicious actors can leverage the improper handling of dynamic library loading to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability stems from the improper parsing of environment variables within the vdrleaktest script. When the script processes the LD_LIBRARY_PATH variable, it incorrectly incorporates a zero-length directory entry that effectively creates an empty path component. This empty component allows the system to search the current working directory for shared libraries, which creates an opportunity for attackers to place malicious shared libraries in the current directory. The vulnerability is particularly concerning because it leverages the default library search behavior of the operating system, where empty path components are interpreted as the current directory.
This flaw directly relates to CWE-427 Uncontrolled Search Path Element, which describes situations where an application searches for libraries or other resources in a path that contains untrusted or uncontrolled elements. The vulnerability also aligns with ATT&CK technique T1068, which covers the use of privilege escalation techniques through the manipulation of dynamic link libraries. The issue demonstrates how seemingly minor configuration errors in environment variable handling can create significant security risks, particularly when applications fail to properly validate or sanitize path components.
The operational impact of this vulnerability is substantial for systems running affected versions of Video Disk Recorder, as it provides local users with a straightforward method to escalate privileges. Attackers can simply place a malicious shared library in the current working directory of the vdrleaktest utility, and when the utility executes, it will load and execute the malicious code with the privileges of the user running the application. This type of vulnerability is particularly dangerous in multi-user environments or systems where VDR is run with elevated privileges, as it could potentially lead to complete system compromise.
The third-party dispute regarding this CVE highlights the importance of proper vulnerability analysis and validation. The dispute centers on the assertion that the script erroneously uses a semicolon instead of a colon in the environment variable context, which would fundamentally alter how the path is interpreted. This dispute underscores the need for careful examination of vulnerability reports and the potential for misinterpretation or incorrect analysis of security issues. However, regardless of the specific implementation details, the core principle remains that improper handling of environment variables can create dangerous privilege escalation opportunities.
Effective mitigation strategies for this vulnerability should focus on proper input validation and environment variable handling within the VDR application. System administrators should ensure that all versions of Video Disk Recorder are updated to patched releases that properly handle library path configurations. Additionally, implementing proper privilege separation and ensuring that applications do not run with unnecessary elevated privileges can reduce the potential impact of such vulnerabilities. The vulnerability also emphasizes the importance of proper code review processes that validate environment variable handling and prevent the inclusion of untrusted or malformed path components in library search paths. Organizations should conduct regular security assessments of their VDR installations and ensure that proper security hardening practices are implemented to prevent similar issues from arising in other applications.