CVE-2009-1383 in mathtex
Summary
by MITRE
The getdirective function in mathtex.cgi in mathTeX, when downloaded before 20090713, allows remote attackers to execute arbitrary commands via shell metacharacters in the dpi tag.
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Analysis
by VulDB Data Team • 08/12/2021
The vulnerability described in CVE-2009-1383 affects the mathTeX software suite, specifically targeting the getdirective function within the mathtex.cgi component. This flaw represents a classic command injection vulnerability that emerged in software versions released prior to July 13, 2009. The vulnerability exists in the way the application processes user input through the dpi tag parameter, which is typically used to specify display resolution for mathematical formula rendering. When maliciously crafted input containing shell metacharacters is passed through this parameter, the application fails to properly sanitize the input before using it in system commands, creating an exploitable condition that allows attackers to execute arbitrary commands on the affected system with the privileges of the web server process.
The technical exploitation of this vulnerability follows the patterns described in CWE-78, which catalogs improper neutralization of special elements used in OS commands. The getdirective function in mathtex.cgi likely constructs shell commands by concatenating user-provided parameters directly into system call invocations without adequate input validation or sanitization. Attackers can leverage this by embedding shell metacharacters such as semicolons, ampersands, or backticks within the dpi tag value, which then get interpreted by the underlying shell when the application executes system commands to process mathematical expressions. This type of vulnerability falls under the ATT&CK technique T1059.001 for command and script injection, where adversaries use legitimate system tools to execute malicious commands.
The operational impact of this vulnerability is significant as it provides remote attackers with arbitrary code execution capabilities on systems running vulnerable versions of mathTeX. Since the vulnerability affects a CGI script that typically runs with web server privileges, successful exploitation could lead to complete system compromise, allowing attackers to access sensitive data, install backdoors, or use the compromised system as a pivot point for further attacks within the network. The vulnerability is particularly dangerous because it requires no authentication to exploit and can be triggered through simple HTTP requests containing malicious payloads. Organizations using outdated mathTeX installations remain at risk, as the vulnerability exists in versions released before the security patch was implemented in July 2009, making it a persistent threat for systems that have not been updated or migrated from legacy software.
Mitigation strategies for CVE-2009-1383 involve immediate software updates to versions released after July 13, 2009, which contain proper input sanitization and validation mechanisms. System administrators should implement comprehensive patch management procedures to ensure all vulnerable applications are updated promptly. Input validation should be strengthened at multiple layers, including validating and sanitizing all user-supplied data before it is processed by any system commands. The principle of least privilege should be enforced by running web applications with minimal required permissions, and additional security measures such as web application firewalls and input filtering mechanisms should be deployed. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in other legacy applications that may be susceptible to command injection attacks. Organizations should also consider migrating from deprecated software suites to more modern, actively maintained alternatives that follow current security best practices and provide regular security updates.