CVE-2010-5250 in Pthreads-win32
Summary
by MITRE
Untrusted search path vulnerability in the pthread_win32_process_attach_np function in pthreadGC2.dll in Pthreads-win32 2.8.0 allows local users to gain privileges via a Trojan horse quserex.dll file in the current working directory. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 02/20/2019
The vulnerability identified as CVE-2010-5250 represents a critical untrusted search path weakness within the pthreads-win32 library implementation specifically affecting version 2.8.0. This flaw exists in the pthread_win32_process_attach_np function located within the pthreadGC2.dll dynamic link library, creating a significant security risk for Windows-based systems utilizing this threading library. The vulnerability stems from the library's improper handling of dynamic library loading processes, where the system searches for required components in predictable locations without adequate validation of source authenticity. This behavior creates an exploitable condition where malicious actors can place specially crafted DLL files in the current working directory to manipulate the execution flow of legitimate applications.
The technical implementation of this vulnerability relies on the Windows dynamic link library loading mechanism and demonstrates a classic privilege escalation vector through DLL hijacking techniques. When an application loads pthreadGC2.dll, the library's pthread_win32_process_attach_np function attempts to locate and load additional components without implementing proper security checks or validating the integrity of the loaded modules. The specific Trojan horse file quserex.dll represents a malicious payload that, when placed in the current working directory, gets loaded instead of the legitimate system component due to the insecure search order. This vulnerability directly maps to CWE-427 Uncontrolled Search Path Element and CWE-428 Untrusted Search Path, both of which are classified under the broader category of insecure library loading practices. The flaw operates at the system level where the operating system's DLL search order mechanism is exploited without proper sandboxing or validation of library sources.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential complete system compromise when exploited in conjunction with other attack vectors. Local users can leverage this weakness to execute arbitrary code with elevated privileges, potentially leading to persistent backdoor installation, data exfiltration, or further exploitation of the compromised system. The vulnerability affects any application that utilizes the pthreads-win32 library version 2.8.0, making it particularly dangerous in enterprise environments where multiple applications might be using this threading library. From an ATT&CK framework perspective, this vulnerability aligns with T1068 Privilege Escalation and T1574 Hijacking Execution Flow techniques, representing a method of executing malicious code through legitimate system processes. The attack surface is particularly wide as any application that dynamically loads pthreadGC2.dll becomes a potential target for exploitation, including development tools, system utilities, and enterprise applications.
Mitigation strategies for CVE-2010-5250 must address both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities. The primary recommendation involves upgrading to a patched version of the pthreads-win32 library where the insecure search path handling has been corrected. Organizations should implement proper DLL loading practices by using LoadLibrary with explicit paths or employing Windows' built-in security features such as DEP (Data Execution Prevention) and ASLR (Address Space Layout Randomization). Additionally, system administrators should conduct comprehensive vulnerability assessments to identify all applications utilizing the affected library version and ensure proper access controls are implemented to prevent unauthorized users from placing malicious DLL files in application directories. The implementation of application whitelisting solutions and regular security audits can help detect and prevent exploitation attempts. Organizations should also consider implementing monitoring solutions that can detect unusual DLL loading patterns or unauthorized file placements in critical directories, providing early warning capabilities for potential exploitation attempts.