CVE-2024-21733: Apache Tomcat Information Disclosure Flaw

CVE-2024-21733 Overview

The vulnerability CVE-2024-21733 pertains to an error message generation issue in Apache Tomcat. This vulnerability leads to the exposure of sensitive information through improperly handled error messages. It affects Apache Tomcat versions 8.5.7 through 8.5.63 and 9.0.0-M11 through 9.0.43. Users are strongly advised to update to version 8.5.64 or 9.0.44 and onward to remediate the vulnerability.

Critical Impact

The vulnerability may result in leakage of sensitive error information that could aid further exploitation.

Affected Products

• Apache Tomcat 8.5.7 - 8.5.63
• Apache Tomcat 9.0.0-M11 - 9.0.43
• Other end-of-life versions may also be affected

Discovery Timeline

• 2024-01-19 - CVE CVE-2024-21733 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2024-21733

Vulnerability Analysis

CVE-2024-21733 exists due to the generation of error messages containing sensitive details during certain operations in Apache Tomcat. This occurs when error details are improperly logged or displayed, which could potentially expose information useful for an attacker.

Root Cause

The root cause lies in inadequate handling of error messages within the affected versions of Apache Tomcat, leading to sensitive information disclosure.

Attack Vector

The vulnerability is exploitable over the network, allowing attackers to trigger the issue remotely by causing the application to generate specific error conditions.

// Example user input triggering an error
try {
    // Simulate application logic
    simulateError();
} catch (Exception e) {
    System.out.println("Sensitive Error: " + e.getMessage());
}

Detection Methods for CVE-2024-21733

Indicators of Compromise

• Presence of detailed error messages in logs or user interfaces
• Logging of sensitive paths or system data as errors
• Access logs showing specific patterns causing errors

Detection Strategies

Utilize application scanning tools configured to identify improper error message handling and sensitive information leakage. Regularly review login and application error logs for unusual error patterns or exposed data.

Monitoring Recommendations

Implement comprehensive logging and alerting for exceptions and error messages within the application stack. Pay attention to high-fidelity alerts that signal deviations from normal error message patterns.

How to Mitigate CVE-2024-21733

Immediate Actions Required

• Immediately upgrade to Apache Tomcat 8.5.64 or 9.0.44
• Review and configure logging policies to prevent sensitive information exposure
• Implement strict access controls to minimize exposure of sensitive logs

Patch Information

The remediation of this vulnerability is available in patches from Apache Tomcat versions 8.5.64 and 9.0.44 onwards.

Workarounds

In addition to applying patches, administrators can enhance system security by setting proper permissions on log files and ensuring sensitive data is not logged.

# Example configuration for sensitive data logging
sed -i 's/log.debug("Sensitive: " + data);//' /path/to/tomcat/source/*.java