CVE-2024-40446: Ctan Mimetex RCE Vulnerability

CVE-2024-40446 Overview

CVE-2024-40446 is a code injection vulnerability discovered in forkosh Mime Tex, a widely used tool for rendering mathematical expressions as images. This vulnerability allows remote attackers to execute arbitrary code on affected systems by providing specially crafted input scripts. The flaw stems from improper input validation within the application, enabling attackers to inject and execute malicious code without authentication.

Critical Impact

Remote attackers can achieve arbitrary code execution on vulnerable systems without requiring authentication or user interaction, potentially leading to complete system compromise.

Affected Products

• CTAN Mimetex versions prior to 1.77
• Forkosh Mime Tex before version 1.77
• Systems and applications integrating vulnerable Mimetex components

Discovery Timeline

• 2025-04-22 - CVE-2024-40446 published to NVD
• 2025-06-23 - Last updated in NVD database

Technical Details for CVE-2024-40446

Vulnerability Analysis

This vulnerability is classified as CWE-94 (Improper Control of Generation of Code), commonly known as Code Injection. The flaw exists in how Mime Tex processes user-supplied input scripts. When a malicious actor submits a specially crafted script to the Mime Tex rendering engine, the application fails to properly sanitize or validate the input before processing. This allows the injected code to be executed within the context of the Mime Tex process, granting the attacker the same privileges as the application.

The network-accessible nature of this vulnerability means that attackers can exploit it remotely without requiring any prior authentication or user interaction. Successful exploitation could result in complete compromise of confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of CVE-2024-40446 lies in insufficient input validation within the Mime Tex script processing functionality. The application does not adequately sanitize user-provided input before incorporating it into executable code paths. This lack of proper input filtering allows attackers to escape the intended context and inject arbitrary commands or code that the system then executes.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no privileges or user interaction. An attacker can exploit this vulnerability by:

1. Identifying a system running a vulnerable version of Mime Tex (prior to version 1.77)
2. Crafting a malicious script payload designed to execute arbitrary code
3. Submitting the crafted payload to the Mime Tex rendering endpoint
4. Achieving code execution with the privileges of the Mime Tex process

The vulnerability mechanism involves improper handling of script input, allowing code injection. Technical details and demonstration can be found in the GitHub PoC Repository and the accompanying video demonstration.

Detection Methods for CVE-2024-40446

Indicators of Compromise

• Unexpected processes spawned by the Mime Tex application or web server
• Unusual network connections originating from systems running Mime Tex
• Log entries showing malformed or suspicious script inputs to Mime Tex endpoints
• Unexpected file system modifications in directories accessible to the Mime Tex process

Detection Strategies

• Monitor web application firewall (WAF) logs for requests containing suspicious script patterns targeting Mime Tex endpoints
• Implement application-level logging to capture all input processed by Mime Tex for forensic analysis
• Deploy intrusion detection systems (IDS) with signatures for code injection patterns in LaTeX/mathematical expression contexts
• Conduct regular vulnerability scanning to identify instances of unpatched Mime Tex installations

Monitoring Recommendations

• Enable verbose logging for all Mime Tex processing activities and forward logs to a centralized SIEM
• Set up alerts for process creation anomalies on systems hosting Mime Tex
• Monitor for unusual CPU or memory consumption patterns that may indicate exploitation attempts
• Review access logs for requests to Mime Tex endpoints from unexpected geographic locations or IP ranges

How to Mitigate CVE-2024-40446

Immediate Actions Required

• Upgrade Mime Tex to version 1.77 or later immediately
• If upgrade is not immediately possible, consider temporarily disabling Mime Tex functionality until patching can occur
• Implement network segmentation to limit exposure of systems running vulnerable Mime Tex versions
• Review and audit all systems for signs of compromise before and after patching

Patch Information

The vulnerability has been addressed in Mime Tex version 1.77 and later releases. Organizations should upgrade to the latest available version to remediate this vulnerability. For detailed information about the vulnerability and remediation guidance, refer to the GitHub PoC Repository.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to filter potentially malicious script inputs targeting Mime Tex
• Implement strict input validation at the application layer to sanitize all user-supplied data before processing
• Restrict network access to Mime Tex endpoints using firewall rules, limiting access to trusted IP ranges only
• Run Mime Tex with minimal privileges using sandboxing or containerization to limit the impact of potential exploitation

# Example: Restrict access to Mime Tex endpoint using iptables
# Allow only trusted network to access the application
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP

# Run Mime Tex in a restricted container environment
# docker run --read-only --security-opt=no-new-privileges mimetex:1.77