CVE-2019-15036 in TeamCity
Summary
by MITRE
An issue was discovered in JetBrains TeamCity 2018.2.4. A TeamCity Project administrator could execute any command on the server machine. The issue was fixed in TeamCity 2018.2.5 and 2019.1.
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Analysis
by VulDB Data Team • 09/20/2020
This vulnerability represents a critical privilege escalation flaw in JetBrains TeamCity 2018.2.4 that allows project administrators to execute arbitrary commands on the underlying server system. The vulnerability stems from insufficient access controls and input validation mechanisms within the TeamCity administrative interface, specifically affecting the command execution functionality that should be restricted to system administrators only. The flaw enables a malicious project administrator to escalate their privileges and gain full control over the server environment through unauthorized command injection attacks.
The technical implementation of this vulnerability involves the improper handling of user input within the project management subsystem of TeamCity. When project administrators attempt to perform certain administrative operations, the system fails to properly validate or sanitize the commands being executed, creating an environment where arbitrary code can be injected and executed with the privileges of the TeamCity server process. This represents a classic command injection vulnerability that falls under the CWE-78 category for improper neutralization of special elements used in OS commands. The vulnerability is particularly dangerous because it allows attackers to execute commands with elevated privileges that would normally be restricted to system administrators.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over the TeamCity server infrastructure. An attacker with project administrator privileges can execute arbitrary system commands including file manipulation, process termination, network reconnaissance, and potential lateral movement within the network. This vulnerability directly maps to ATT&CK techniques such as privilege escalation and command and control operations, enabling attackers to establish persistent access and potentially compromise other systems within the network infrastructure. The exposure of this vulnerability in a continuous integration/continuous deployment environment is particularly concerning as TeamCity servers often have access to sensitive development environments and production systems.
Mitigation strategies for this vulnerability require immediate patching of affected TeamCity installations to versions 2018.2.5 or 2019.1 where the issue has been resolved. Organizations should also implement network segmentation to isolate TeamCity servers from critical infrastructure and enforce the principle of least privilege for project administrators. Additional protective measures include monitoring for unusual command execution patterns, implementing strict input validation controls, and conducting regular security assessments of the TeamCity installation. The vulnerability highlights the importance of proper access control implementation and input validation in enterprise software environments where administrative functions can have significant system-wide implications. Security teams should also consider implementing automated patch management processes to ensure timely deployment of security updates and reduce the window of exposure for similar vulnerabilities.