CVE-2009-2944 in ikiwiki
Summary
by MITRE
Incomplete blacklist vulnerability in the teximg plugin in ikiwiki before 3.1415926 and 2.x before 2.53.4 allows context-dependent attackers to read arbitrary files via crafted TeX commands.
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Analysis
by VulDB Data Team • 03/30/2025
The vulnerability identified as CVE-2009-2944 represents a critical security flaw in the teximg plugin of ikiwiki software versions prior to 3.1415926 and 2.x versions before 2.53.4. This issue stems from an incomplete blacklist implementation that fails to properly validate user-supplied TeX commands, creating a significant attack surface for context-dependent adversaries seeking unauthorized file access. The vulnerability specifically affects the processing of mathematical expressions within the wiki system, where TeX commands are interpreted and rendered as images, making it a prime target for privilege escalation and information disclosure attacks.
The technical flaw manifests through the inadequate filtering mechanism that attempts to block potentially dangerous file access patterns but fails to account for various obfuscation techniques and alternative command structures that can bypass the restrictions. Attackers can craft malicious TeX commands that exploit the incomplete blacklist to traverse file system paths and read arbitrary files on the server hosting the ikiwiki instance. This vulnerability operates under the principle of input validation failure, where the system assumes that certain command patterns are sufficient to prevent malicious file access, while overlooking legitimate but dangerous variations that can be constructed through context-dependent command manipulation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable attackers to access sensitive configuration files, user credentials, system logs, and other confidential data stored within the file system. The context-dependent nature of the attack means that successful exploitation requires understanding of the target environment's file structure and the specific conditions under which the vulnerability can be triggered. This makes the vulnerability particularly dangerous in environments where ikiwiki is used for collaborative documentation, knowledge management, or internal wiki systems where sensitive organizational information is stored.
Mitigation strategies for this vulnerability require implementing proper input sanitization and validation mechanisms that go beyond simple blacklist approaches. Organizations should upgrade to patched versions of ikiwiki that address the incomplete blacklist issue and implement more robust security measures such as whitelist-based validation, sandboxed execution environments for TeX command processing, and comprehensive file access controls. The vulnerability aligns with CWE-20, which describes improper input validation, and can be mapped to ATT&CK technique T1059.001 for command and scripting interpreter execution. Additionally, the issue demonstrates characteristics of privilege escalation through file system access, which may relate to ATT&CK technique T1078 for valid accounts and T1566 for malicious file execution. System administrators should also consider implementing network segmentation, monitoring for suspicious TeX command patterns, and regular security audits to prevent exploitation of this and similar vulnerabilities.