CVE-2017-2648 in jenkins-ssh-slaves-plugin
Summary
by MITRE
It was found that jenkins-ssh-slaves-plugin before version 1.15 did not perform host key verification, thereby enabling Man-in-the-Middle attacks.
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Analysis
by VulDB Data Team • 04/27/2023
The vulnerability identified as CVE-2017-2648 affects the jenkins-ssh-slaves-plugin version 1.15 and earlier, representing a critical security flaw that undermines the integrity of SSH communications within Jenkins environments. This issue stems from the plugin's failure to implement proper host key verification mechanisms during SSH connections, creating an exploitable gap that adversaries can leverage to compromise the security posture of automated build and deployment systems.
The technical flaw resides in the plugin's implementation of SSH connections where it does not validate the host key presented by remote servers during the initial handshake process. According to CWE-310, this represents a weakness in cryptographic key management and authentication protocols, specifically failing to implement proper host key verification as outlined in RFC 4252 for SSH communications. The absence of host key verification means that Jenkins slaves can establish connections to any SSH server without confirming the server's identity, making the system susceptible to man-in-the-middle attacks where attackers can intercept and manipulate communication between Jenkins masters and slave nodes.
The operational impact of this vulnerability extends beyond simple network interception, as it fundamentally compromises the trust model that secure automation systems rely upon. When attackers can successfully perform man-in-the-middle attacks against Jenkins SSH connections, they gain the ability to execute arbitrary code on build agents, potentially leading to complete system compromise. This vulnerability directly aligns with ATT&CK technique T1021.004 for remote services and T1566 for credential harvesting, as it enables attackers to establish persistent access points within CI/CD pipelines. The compromised Jenkins environment becomes a potential launchpad for further attacks within the network infrastructure, particularly in enterprise environments where Jenkins serves as a central automation hub for software delivery processes.
Organizations utilizing affected versions of the jenkins-ssh-slaves-plugin should immediately upgrade to version 1.15 or later, which implements proper host key verification mechanisms. Additionally, administrators should implement comprehensive monitoring of SSH connections and host key changes within their Jenkins environments. Security teams should conduct thorough audits of all SSH-based automation tools and ensure that proper key management practices are implemented across all CI/CD infrastructure. The vulnerability demonstrates the critical importance of maintaining secure communication channels in automated systems, particularly those handling sensitive code deployment processes where trust verification is paramount for maintaining system integrity and preventing unauthorized access to development and production environments.