EUVD-2025-10673

Comprehensive Technical Analysis of EUVD-2025-10673

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2025-10673 pertains to the jenkins/ssh-slave Docker images based on Debian. The issue arises from the generation of SSH host keys during image creation, leading to all containers derived from the same image version sharing identical SSH host keys. This flaw allows attackers to perform man-in-the-middle (MITM) attacks by impersonating the SSH build agent, thereby intercepting communications between the Jenkins controller and the SSH build agent.

Severity Evaluation:

• Base Score: 9.1 (CVSS 3.1)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

The high base score indicates a critical vulnerability due to the potential for significant confidentiality and integrity impacts. The attack vector is network-based (AV:N), requires low complexity (AC:L), and does not necessitate privileged access (PR:N) or user interaction (UI:N). The scope is unchanged (S:U), but the confidentiality and integrity impacts are high (C:H, I:H), while availability impact is none (A:N).

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Man-in-the-Middle (MITM) Attacks: An attacker can insert themselves into the network path between the Jenkins controller and the SSH build agent, impersonating the latter due to the shared SSH host keys.
• SSH Key Spoofing: Attackers can spoof the SSH host keys to gain unauthorized access to the Jenkins build environment.

Exploitation Methods:

• Network Interception: Using tools like ARP spoofing, DNS spoofing, or other network interception techniques to position themselves between the Jenkins controller and the SSH build agent.
• Key Replacement: Replacing the legitimate SSH host keys with malicious ones to intercept and manipulate communications.

3. Affected Systems and Software Versions

Affected Systems:

• Jenkins environments using jenkins/ssh-slave Docker images based on Debian.

Software Versions:

• Specific versions of jenkins/ssh-slave Docker images that generate SSH host keys during image creation.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Regenerate SSH Host Keys: Ensure that SSH host keys are regenerated during container initialization rather than during image creation.
• Unique Keys per Container: Implement a mechanism to generate unique SSH host keys for each container instance.

Long-Term Mitigation:

• Update Docker Images: Update to a version of the jenkins/ssh-slave Docker image that addresses this vulnerability.
• Network Security: Implement robust network security measures such as VPNs, secure tunnels, and strict access controls to prevent MITM attacks.
• Monitoring and Logging: Enhance monitoring and logging to detect any suspicious activities or unauthorized access attempts.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations using Jenkins for continuous integration and continuous deployment (CI/CD) pipelines, particularly those in the European Union. The potential for MITM attacks can lead to data breaches, unauthorized access, and compromised build environments, affecting the integrity and confidentiality of software development processes. This underscores the need for vigilant security practices and timely updates in CI/CD environments.

6. Technical Details for Security Professionals

Vulnerability Details:

• CVE ID: CVE-2025-32755
• Assigner: Jenkins Project
• Product: Jenkins jenkins/ssh-slave Docker images
• Product Version: Patch: alpine

References:

• Jenkins Security Advisory
• NVD Detail

Technical Recommendations:

• Key Management: Implement a secure key management system to ensure unique and secure SSH host keys for each container.
• Container Security: Regularly update and audit Docker images for security vulnerabilities.
• Intrusion Detection: Deploy intrusion detection systems (IDS) to monitor for suspicious activities within the Jenkins environment.

Conclusion: The vulnerability in jenkins/ssh-slave Docker images based on Debian highlights the importance of secure key management and robust network security in CI/CD pipelines. Organizations should prioritize updating affected systems and implementing recommended mitigation strategies to protect against potential exploitation.

This analysis provides a comprehensive overview of the vulnerability, its potential impacts, and the necessary steps to mitigate risks, ensuring the security and integrity of Jenkins environments.