EUVD-2024-3537

Comprehensive Technical Analysis of EUVD-2024-3537

1. Vulnerability Assessment and Severity Evaluation

Vulnerability Description: The vulnerability EUVD-2024-3537, also known as CVE-2024-50379, is a Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability affecting Apache Tomcat during JSP compilation. This issue arises when the default servlet is enabled for write, a non-default configuration, on case-insensitive file systems.

Severity Evaluation: The vulnerability has a CVSS Base Score of 9.8, which is considered critical. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H indicates the following:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

This high severity score underscores the critical nature of the vulnerability, which can lead to Remote Code Execution (RCE), potentially compromising the confidentiality, integrity, and availability of the affected systems.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attacks: Given the CVSS vector, the vulnerability can be exploited over the network without requiring any special privileges or user interaction.
• Race Condition Exploitation: An attacker could exploit the TOCTOU race condition by manipulating the timing of file checks and usage during JSP compilation. This could allow the attacker to inject malicious code that gets executed by the server.

Exploitation Methods:

• File Manipulation: An attacker could manipulate the files being checked and used during the JSP compilation process to introduce malicious code.
• Code Injection: By exploiting the race condition, an attacker could inject and execute arbitrary code on the server, leading to RCE.

3. Affected Systems and Software Versions

Affected Versions:

• Apache Tomcat 11.0.0-M1 through 11.0.1
• Apache Tomcat 10.1.0-M1 through 10.1.33
• Apache Tomcat 9.0.0.M1 through 9.0.97

Non-Affected Versions:

• Apache Tomcat 11.0.2
• Apache Tomcat 10.1.34
• Apache Tomcat 9.0.98

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Upgrade: Users are strongly recommended to upgrade to the patched versions: 11.0.2, 10.1.34, or 9.0.98.
• Disable Write Permissions: Ensure that the default servlet is not enabled for write permissions, which is the non-default configuration that exposes the vulnerability.

Long-Term Mitigation:

• Regular Patching: Implement a regular patching and update schedule for all software components.
• Configuration Review: Conduct a thorough review of server configurations to ensure they adhere to best security practices.
• Monitoring and Logging: Enhance monitoring and logging to detect any suspicious activities that may indicate an exploitation attempt.

5. Impact on European Cybersecurity Landscape

Regulatory Compliance:

• GDPR: Organizations must ensure that they comply with GDPR regulations by promptly addressing vulnerabilities that could lead to data breaches.
• NIS Directive: Critical infrastructure providers must adhere to the Network and Information Systems (NIS) Directive, which mandates robust cybersecurity measures.

Economic Impact:

• Business Continuity: Exploitation of this vulnerability could lead to significant disruptions in business operations, affecting revenue and customer trust.
• Reputation: Organizations that fail to address this vulnerability could face reputational damage if a breach occurs.

6. Technical Details for Security Professionals

Technical Overview:

• TOCTOU Race Condition: This vulnerability exploits the timing difference between the check and use of files during JSP compilation. On case-insensitive file systems, this discrepancy can be leveraged to inject malicious code.
• Default Servlet Configuration: The vulnerability is triggered when the default servlet is configured to allow write permissions, which is not the default setting.

Detection and Response:

• Intrusion Detection Systems (IDS): Deploy IDS to detect unusual network activities that may indicate an exploitation attempt.
• File Integrity Monitoring (FIM): Implement FIM to monitor changes to critical files and directories, which can help detect unauthorized modifications.
• Incident Response Plan: Ensure that an incident response plan is in place to quickly address any detected exploitation attempts.

References:

• NVD: CVE-2024-50379
• GitHub Commits:
  • Commit 05ddeeaa54df1e2dc427d0164bedd6b79f78d81f
  • Commit 43b507ebac9d268b1ea3d908e296cc6e46795c00
  • Commit 631500b0c9b2a2a2abb707e3de2e10a5936e5d41
  • Commit 684247ae85fa633b9197b32391de59fc54703842
  • Commit 8554f6b1722b33a2ce8b0a3fad37825f3a75f2d2
  • Commit cc7a98b57c6dc1df21979fcff94a36e068f4456c

Additional Resources:

• Apache Tomcat Security Advisories:
  • Tomcat 10.1.34
  • Tomcat 11.0.2
  • Tomcat 9.0.98

By addressing this vulnerability promptly and comprehensively, organizations can significantly reduce the risk of exploitation and ensure the security and integrity of their systems.