CVE-2019-18366 in TeamCity
Summary
by MITRE
In JetBrains TeamCity before 2019.1.2, secure values could be exposed to users with the "View build runtime parameters and data" permission.
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Analysis
by VulDB Data Team • 11/01/2019
This vulnerability exists in JetBrains TeamCity versions prior to 2019.1.2 where secure values are improperly exposed to users who possess the "View build runtime parameters and data" permission. The flaw represents a critical authorization bypass that allows unauthorized users to access sensitive configuration data that should remain protected. Secure values in TeamCity typically include passwords, API keys, and other confidential information used during build processes. The vulnerability stems from insufficient access controls that fail to properly validate user permissions when exposing runtime parameters. This issue directly violates the principle of least privilege and demonstrates a failure in the application's information flow control mechanisms.
The technical implementation of this vulnerability occurs at the permission validation layer within TeamCity's security architecture. When users with limited permissions attempt to access build runtime parameters, the system fails to properly separate secure values from non-sensitive data during the rendering process. This allows the exposure of encrypted or obfuscated secure values that should only be accessible to users with elevated privileges such as administrators or build runners. The flaw can be categorized under CWE-284: Improper Access Control, which specifically addresses inadequate access control mechanisms that allow unauthorized access to resources. The vulnerability affects the confidentiality aspect of the CIA triad by enabling unauthorized disclosure of sensitive build-time information.
From an operational perspective, this vulnerability poses significant risks to organizations using TeamCity for continuous integration and deployment processes. Attackers who can escalate to the "View build runtime parameters and data" permission level can extract sensitive credentials and configuration details that may be used to compromise other systems within the organization's infrastructure. The impact extends beyond immediate credential theft to potentially enable further attacks including lateral movement, privilege escalation, and data exfiltration. The vulnerability is particularly concerning because it can be exploited by users who may not have direct administrative access but can still gain access through legitimate means such as being granted specific build viewing permissions. This aligns with ATT&CK technique T1552: Unsecured Credentials, which focuses on accessing credentials that are not properly protected. The exposure of secure values can lead to supply chain attacks, as compromised credentials may provide access to downstream systems, repositories, and services.
Organizations should immediately upgrade to TeamCity version 2019.1.2 or later to remediate this vulnerability. The upgrade addresses the underlying access control implementation by properly validating user permissions before exposing secure values in runtime parameter displays. Additional mitigations include implementing stricter permission controls, regularly auditing user access rights, and monitoring for unauthorized access attempts to build parameters. Security teams should also consider implementing network segmentation and additional monitoring controls to detect potential exploitation attempts. The vulnerability highlights the importance of proper input validation and access control implementation in CI/CD environments where sensitive data flows through automated processes. Organizations should also review their overall security posture in development environments and ensure that secure values are properly managed throughout the software development lifecycle to prevent similar issues in other tools and platforms.