CVE-2011-5156 in Effective File Search
Summary
by MITRE
Untrusted search path vulnerability in Effective File Search 6.7 allows local users to gain privileges via a Trojan horse ztvunrar36.dll file in the current working directory, as demonstrated by a directory that contains a .efs file. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 01/25/2018
The vulnerability identified as CVE-2011-5156 represents a classic untrusted search path issue affecting Effective File Search version 6.7, classified under CWE-427 Untrusted Search Path. This security flaw exploits the software's improper handling of dynamic library loading mechanisms, where the application fails to validate the source and authenticity of dynamically linked libraries loaded from the current working directory. The vulnerability specifically manifests when the application encounters a .efs file in a directory, triggering a chain of events that allows local attackers to execute malicious code with elevated privileges.
The technical exploitation of this vulnerability relies on the principle of dynamic link library hijacking, where attackers place a malicious DLL file named ztvunrar36.dll in the same directory as a legitimate .efs file. When Effective File Search processes this file, it loads the malicious DLL from the current working directory instead of the intended system locations, effectively executing attacker-controlled code within the context of the application. This privilege escalation occurs because the application does not implement proper path validation or library integrity checks during the dynamic loading process, creating an environment where malicious code can be seamlessly integrated into the legitimate application flow.
From an operational perspective, this vulnerability poses significant risks to systems where Effective File Search is installed, as it allows local attackers with minimal privileges to escalate their access level and potentially compromise the entire system. The attack vector is particularly concerning because it requires only local access and does not necessitate network connectivity or complex attack chains. The vulnerability demonstrates how seemingly benign file processing operations can become entry points for privilege escalation, making it a critical concern for system administrators who may not expect such behavior from file search utilities. The impact extends beyond immediate privilege escalation, potentially allowing attackers to establish persistent access, exfiltrate sensitive data, or deploy additional malware within the compromised environment.
Mitigation strategies for CVE-2011-5156 should focus on implementing proper library loading practices and addressing the root cause of the untrusted search path issue. System administrators should ensure that Effective File Search is updated to a patched version that properly validates library paths and implements secure coding practices to prevent DLL hijacking. The recommended approach includes enforcing strict path validation, using absolute paths for library loading, and implementing proper file integrity checks. Additionally, security measures such as application whitelisting, restricted user permissions, and regular security audits can help prevent exploitation of this vulnerability. Organizations should also consider implementing monitoring solutions to detect unusual file loading patterns and potential DLL injection attempts, aligning with ATT&CK technique T1055 for process injection and T1574 for hijacking execution flow. The vulnerability underscores the importance of secure coding practices and proper library management in preventing exploitation of similar search path vulnerabilities across different software applications.