CVE-2018-1000057 in Credentials Binding Plugin
Summary
by MITRE
Jenkins Credentials Binding Plugin 1.14 and earlier masks passwords it provides to build processes in their build logs. Jenkins however transforms provided password values, e.g. replacing environment variable references, which could result in values different from but similar to configured passwords being provided to the build. Those values are not subject to masking, and could allow unauthorized users to recover the original password.
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Analysis
by VulDB Data Team • 01/03/2020
The vulnerability identified as CVE-2018-1000057 affects the Jenkins Credentials Binding Plugin version 1.14 and earlier, presenting a significant security risk in credential management within continuous integration environments. This issue stems from the plugin's handling of password values during build processes where the system masks passwords in build logs to prevent exposure. However, the masking mechanism operates only on the original password values as they are initially provided to the build environment, creating a critical gap in security controls.
The technical flaw in this vulnerability lies in Jenkins' transformation process of password values, which involves replacing environment variable references and other substitutions before delivering credentials to build processes. This transformation process, while seemingly benign, introduces a dangerous discrepancy between the masked password displayed in logs and the actual value passed to the build environment. The system's failure to apply consistent masking across all instances of credential values means that transformed password values, which may differ from the original configured passwords but remain functionally equivalent, escape the masking protection mechanism.
The operational impact of this vulnerability extends beyond simple credential exposure, as it creates a potential attack vector for unauthorized users who can potentially recover original password values through careful analysis of build logs. Attackers can exploit this weakness by monitoring build processes where transformed password values are not masked, allowing them to reconstruct the original credentials even when the direct password values are obscured. This creates a sophisticated attack surface where attackers can leverage the system's own transformation mechanisms against it, undermining the fundamental security assumptions of credential handling within Jenkins environments.
Security professionals should recognize this vulnerability as a variant of CWE-200 Information Exposure, specifically related to inadequate protection of sensitive data during processing operations. The issue aligns with ATT&CK technique T1552.001 Unsecured Credentials, where credential information is exposed through improper handling of sensitive data in automated processes. Organizations using Jenkins should implement immediate mitigations including upgrading to plugin versions 1.15 and later, which address the masking inconsistency, and establishing additional logging controls to monitor for credential usage patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining consistent security controls throughout all stages of data processing, particularly when handling sensitive information such as authentication credentials in automated build environments.