CVE-2024-56337: Apache Tomcat Race Condition Vulnerability

CVE-2024-56337 Overview

Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Apache Tomcat affects multiple versions, including versions that are End-of-Life (EOL).

This vulnerability occurs in Apache Tomcat (11.0.0-M1 through 11.0.1, 10.1.0-M1 through 10.1.33, 9.0.0.M1 through 9.0.97, and 8.5.0 though 8.5.100) due to improper handling of the sun.io.useCanonCaches system property.

Critical Impact
This vulnerability has a CVSS score of 9.8, making it a critical issue that can lead to complete system compromise.

Affected Products

Apache Tomcat
NetApp Bootstrap OS
NetApp HCI Compute Node

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Apache
Not Available - CVE CVE-2024-56337 assigned
Not Available - Apache releases security patch
2024-12-20T16:15:24.260 - CVE CVE-2024-56337 published to NVD
2025-11-03T21:17:51.027 - Last updated in NVD database

Technical Details for CVE-2024-56337

Vulnerability Analysis

This vulnerability is a Time-of-check Time-of-use (TOCTOU) issue that arises when Tomcat is run on a case-insensitive file system with the default servlet write enabled. The incomplete mitigation for CVE-2024-50379 leads to potential race conditions during file handling operations.

Root Cause

The root of this vulnerability lies in the caching mechanism associated with the sun.io.useCanonCaches system property. Inappropriate default configurations and insufficient validation checks allow exploitation.

Attack Vector

The vulnerability can be exploited remotely over the network, presenting a significant threat due to its ease of access and lack of required privileges.

java

// Example exploitation code (sanitized)
Runtime.getRuntime().exec("malicious-command");

Detection Methods for CVE-2024-56337

Indicators of Compromise

Unusual file modifications on case-insensitive file systems
Unauthorized changes or execution of commands
Log discrepancies associated with servlet operations

Detection Strategies

Implement logging and monitoring for changes in the servlet's execution path and track system property modifications in real-time to catch anomalies before full exploitation.

Monitoring Recommendations

Regularly audit and inspect Tomcat server logs for suspicious activities, focusing on file permission and execution anomalies. Use Security Information and Event Management (SIEM) systems to detect early indicators of race condition exploitation.

How to Mitigate CVE-2024-56337

Immediate Actions Required

Disable the default servlet's write capabilities where not needed
Verify and configure sun.io.useCanonCaches correctly for JVMs below Java 21
Update to a patched version of Apache Tomcat

Patch Information

Tomcat versions 11.0.3, 10.1.35, and 9.0.99 and onwards contain necessary checks and defaults to mitigate this issue effectively.

Workarounds

For Java 8 or 11, explicitly set the sun.io.useCanonCaches system property to false:

bash

# Configuration example
export JAVA_OPTS="-Dsun.io.useCanonCaches=false"