CVE-2022-39311 is a vulnerability identified in GoCD, a continuous delivery server used to automate and streamline build-test-release cycles. The flaw exists in GoCD versions prior to 21.1.0 and relates to the deserialization of untrusted data (CWE-502) via the Spring RemoteInvocation endpoint, which is used for communication between the GoCD server and its agents. This endpoint improperly handles serialized Java objects sent from agents, allowing an attacker with agent-level authentication to send malicious serialized objects that the server will deserialize. This can lead to remote code execution (RCE) on the GoCD server, effectively allowing an attacker to execute arbitrary code with the privileges of the GoCD server process. Exploitation requires that the attacker either compromise an existing agent, intercept or manipulate network communication between an agent and the server, or successfully register a new malicious agent with valid credentials. There are no known workarounds, and the vulnerability was addressed by GoCD in version 21.1.0. No public exploits have been reported in the wild to date. The vulnerability is rated medium severity, reflecting the requirement for agent-level authentication and the complexity of exploitation, but the potential impact of RCE on critical CI/CD infrastructure is significant. This vulnerability highlights the risks of insecure deserialization in distributed build and deployment systems where trust boundaries between server and agents are critical.

For European organizations, the impact of this vulnerability can be substantial, particularly for those relying on GoCD for their continuous integration and continuous delivery pipelines. Successful exploitation could allow attackers to execute arbitrary code on the GoCD server, potentially leading to full compromise of the build and deployment infrastructure. This could result in unauthorized code injection, tampering with build artifacts, insertion of backdoors into software releases, or disruption of the software delivery process. Such compromises can undermine software integrity, lead to data breaches, and cause significant operational downtime. Given the central role of CI/CD servers in modern DevOps environments, exploitation could cascade to downstream systems and production environments. The requirement for agent-level authentication reduces the attack surface but does not eliminate risk, especially in environments where agent credentials or network security are weak. European organizations in sectors with high regulatory requirements (e.g., finance, healthcare, critical infrastructure) could face compliance violations and reputational damage if this vulnerability is exploited.

1. Immediate upgrade of all GoCD servers and agents to version 21.1.0 or later to apply the official patch addressing this vulnerability. 2. Restrict and tightly control agent registration processes to prevent unauthorized agents from connecting to the GoCD server. Implement strong authentication and authorization mechanisms for agents. 3. Monitor network traffic between agents and the GoCD server for anomalies or unauthorized access attempts, employing network segmentation to isolate build infrastructure. 4. Regularly audit and rotate agent credentials and keys to reduce the risk of credential compromise. 5. Implement runtime application self-protection (RASP) or endpoint detection and response (EDR) solutions on GoCD servers to detect unusual process behavior indicative of exploitation attempts. 6. Review and harden the security posture of the build environment, including limiting server privileges and applying the principle of least privilege to GoCD processes. 7. Conduct security awareness training for DevOps teams to recognize the importance of securing CI/CD pipelines and agent credentials. 8. If upgrading immediately is not feasible, temporarily disable or restrict agent communication endpoints where possible, though no official workaround exists.