CVE-2025-31722

Remediation/Mitigation Strategy for CVE-2025-31722 - Jenkins Templating Engine Plugin Vulnerability

Vulnerability Description:

  • CVE ID: CVE-2025-31722
  • Affected Software: Jenkins Templating Engine Plugin version 2.5.3 and earlier.
  • Description: This vulnerability allows attackers with Item/Configure permission to execute arbitrary code in the context of the Jenkins controller JVM. Libraries defined in folders within the plugin are not subject to sandbox protection, enabling this exploitation.

Severity:

  • CVSS Score: 8.8 (High)
  • CVSS Vector: (Based on provided data: Likely AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) - Network, Low Attack Complexity, Low Privileges Required, No User Interaction, Unchanged Scope, High Confidentiality impact, High Integrity impact, High Availability Impact.
  • Severity Level: High - Due to the ability to achieve Remote Code Execution (RCE).

Known Exploit:

  • The vulnerability exists because libraries defined in folders within the Jenkins Templating Engine plugin are not subject to sandbox protection. An attacker who can configure the Item can inject malicious code into the templating engine, and because there is no sandbox, this code is executed in the context of the Jenkins controller JVM.
  • Exploitability Details: An attacker with Item/Configure permission can modify a template to include calls to malicious code located in an unprotected library folder. This code is then executed when the template is rendered, giving the attacker control of the Jenkins controller.

Remediation/Mitigation Strategy:

  1. Immediate Action: Upgrade the Jenkins Templating Engine Plugin:

    • The primary and most effective remediation is to upgrade the Jenkins Templating Engine Plugin to a version later than 2.5.3 (e.g., if 2.5.4 or later is available). Check the Jenkins plugin repository or the plugin documentation for the latest available version.
    • Steps to Upgrade:
      • Log in to your Jenkins instance as an administrator.
      • Navigate to “Manage Jenkins” -> “Manage Plugins”.
      • Go to the “Updates” tab and check if an update is available for the “Jenkins Templating Engine Plugin”.
      • If an update is available, select the plugin and click “Download now and install after restart”.
      • After the download completes, restart Jenkins. It is highly recommended to restart during off-peak hours to minimize disruption.

  2. Restrict User Permissions (Interim Mitigation if Upgrade is not Immediately Possible):

    • As a temporary mitigation measure, carefully review and restrict Item/Configure permissions. Only grant these permissions to users who absolutely require them and are trusted. Consider implementing a least-privilege access model.
    • Steps to Restrict Permissions:
      • Navigate to “Manage Jenkins” -> “Manage Users”.
      • Review the permissions assigned to each user, especially those with Item/Configure permission.
      • Use a matrix authorization strategy plugin to grant the Item/Configure permission granularly.
      • Revoke Item/Configure permission from any users who do not absolutely require it.

  3. Code Review (If Custom Templates Are Used):

    • If you are using custom templates with the Jenkins Templating Engine Plugin, perform a thorough code review to identify any potential injection points or areas where malicious code could be inserted.
    • Look for:
      • External calls or libraries that are not properly validated.
      • Input fields that are not sanitized or escaped.
      • Any possibility of code injection via template parameters.

  4. Monitor System Logs:

    • Enable detailed logging for the Jenkins instance. Monitor the system logs for any suspicious activity, such as unauthorized access attempts or unexpected code execution.

  5. Web Application Firewall (WAF) Rule (Advanced Mitigation):

    • If you have a WAF in front of your Jenkins instance, consider creating a rule to detect and block any requests that attempt to exploit this vulnerability. This is a complex task and requires a deep understanding of the vulnerability.

  6. Regular Security Audits:

    • Implement regular security audits of your Jenkins environment to identify and address any potential vulnerabilities.

  7. Stay Informed:

    • Subscribe to security advisories from the Jenkins project (e.g., [email protected]) to stay informed about new vulnerabilities and security updates.

Testing After Remediation:

  • After upgrading the plugin, thoroughly test the Jenkins environment to ensure that all functionality is working as expected.
  • Run penetration tests to verify that the vulnerability has been successfully remediated.

Disclaimer: This remediation strategy is based on the information provided and general security best practices. The effectiveness of these measures may vary depending on your specific environment and configuration. Always consult with security experts to tailor the remediation strategy to your specific needs.

Assigner

Date

  • Published Date: 2025-04-02 15:16:00
  • Updated Date: 2025-04-02 17:15:51

More Details

CVE-2025-31722