CVE-2012-2120 in texlive-extra-utils
Summary
by MITRE
latex2man in texlive-extra-utils 2011.20120322, and possibly other versions or packages, when used with the H or T option, allows local users to overwrite arbitrary files via a symlink attack on a temporary file.
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Analysis
by VulDB Data Team • 02/17/2019
The vulnerability identified as CVE-2012-2120 affects the latex2man utility within the texlive-extra-utils package version 2011.20120322 and potentially other versions or packages. This flaw manifests when the utility is invoked with either the H or T command-line options, creating a dangerous race condition that enables local attackers to manipulate the file system through symbolic link attacks. The core issue lies in the improper handling of temporary files during the conversion process from latex to man pages, where the application creates temporary files without adequate security measures to prevent symlink-based file overwrites.
The technical implementation of this vulnerability stems from the application's failure to properly validate or secure temporary file creation processes. When latex2man processes documents with the H or T options, it generates temporary files that are susceptible to symlink attacks. An attacker can establish symbolic links with predetermined names in directories where the utility creates temporary files, effectively allowing them to redirect the utility's write operations to arbitrary locations on the file system. This type of vulnerability is classified as a race condition attack pattern, specifically aligning with CWE-367 which addresses time-of-check to time-of-use vulnerabilities. The flaw represents a classic example of insecure temporary file handling where the utility creates files with predictable names in world-writable directories without proper access control verification.
The operational impact of this vulnerability extends beyond simple file overwrites, as it provides local attackers with the capability to modify critical system files or inject malicious content into the targeted locations. An attacker could potentially overwrite configuration files, system binaries, or other sensitive files with malicious content, leading to privilege escalation or persistent backdoors within the affected system. The vulnerability is particularly concerning in multi-user environments where local access is available, as it allows users to gain unauthorized write access to files they would normally not be able to modify. The attack requires local system access but does not require elevated privileges, making it a significant concern for system administrators who must consider the potential for insider threats or compromised user accounts.
Mitigation strategies for this vulnerability involve multiple layers of security measures that address both the immediate flaw and broader system security. The most effective approach is to upgrade to a patched version of the texlive-extra-utils package where the temporary file handling has been corrected to prevent symlink attacks. System administrators should also implement proper file system permissions, ensuring that temporary directories are not world-writable and that applications create temporary files with unique names and proper access controls. Additional mitigations include running the application with reduced privileges, implementing mandatory access controls, and monitoring for suspicious file creation patterns. The vulnerability demonstrates the importance of following secure coding practices such as those outlined in the OWASP Secure Coding Guidelines and aligns with ATT&CK technique T1059 for command and script injection, as attackers may exploit this vulnerability to execute malicious code through compromised temporary files. Organizations should also consider implementing automated vulnerability scanning tools to detect similar insecure temporary file handling patterns in other software components and ensure comprehensive system hardening practices are maintained across all system utilities.