CVE-2011-2764 in Tremulous
Summary
by MITRE
The FS_CheckFilenameIsNotExecutable function in qcommon/files.c in the ioQuake3 engine 1.36 and earlier, as used in World of Padman, Smokin Guns, OpenArena, Tremulous, and ioUrbanTerror, does not properly determine dangerous file extensions, which allows remote attackers to execute arbitrary code via a crafted third-party addon that creates a Trojan horse DLL file.
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Analysis
by VulDB Data Team • 11/17/2021
The vulnerability identified as CVE-2011-2764 resides within the ioQuake3 engine version 1.36 and earlier implementations, specifically within the FS_CheckFilenameIsNotExecutable function located in qcommon/files.c. This critical flaw affects multiple first-person shooter games including World of Padman, Smokin Guns, OpenArena, Tremulous, and ioUrbanTerror, creating a widespread security concern across the quake-based gaming ecosystem. The issue stems from inadequate validation of file extensions during the addon installation process, which creates a pathway for malicious actors to bypass security mechanisms designed to prevent execution of potentially harmful files.
The technical flaw manifests in the improper determination of dangerous file extensions, particularly failing to recognize Trojan horse DLL files that could be disguised as legitimate game components. When third-party addons are installed, the vulnerable engine does not adequately sanitize filenames or validate file types, allowing attackers to craft malicious files with extensions that appear benign but actually execute arbitrary code on the target system. This vulnerability represents a classic case of insufficient input validation and improper access control, with the flaw directly enabling privilege escalation through file system manipulation.
Operationally, this vulnerability exposes users to significant risks including remote code execution, system compromise, and potential data theft. Attackers can exploit this weakness by creating malicious addons that appear legitimate but contain hidden malicious payloads, particularly targeting Windows systems where DLL files are commonly used for legitimate system functions. The impact extends beyond individual user systems to potentially affect entire gaming communities, as compromised addons can be distributed through official modding platforms and community repositories, creating a vector for widespread exploitation. This vulnerability directly maps to CWE-20, which describes improper input validation, and aligns with ATT&CK technique T1059 for command and scripting interpreter execution.
Mitigation strategies for CVE-2011-2764 require immediate patching of affected ioQuake3 engine versions to implement proper file extension validation and enhanced file type checking. Administrators should enforce strict addon approval processes and implement file integrity monitoring to detect unauthorized modifications. System administrators should also consider implementing application whitelisting policies and restricting user privileges when installing third-party content. The remediation process should include comprehensive security audits of existing addons and immediate removal of any suspicious or unverified content from affected game installations. Organizations should also establish secure development practices for game engine modifications and implement robust code review processes to prevent similar vulnerabilities from being introduced in future versions of the software.