CVE-2025-54538 is a medium-severity vulnerability affecting JetBrains TeamCity versions prior to 2025.07. The vulnerability is classified under CWE-312, which refers to the cleartext storage or transmission of sensitive information. Specifically, this issue arises from the exposure of passwords via the command line when executing the "hg pull" command within TeamCity. Mercurial (hg) is a distributed version control system, and TeamCity integrates with it for source control operations. When the "hg pull" command is run, the password used for authentication can be exposed in the command line arguments, which are often visible to other users on the same system through process inspection tools or logs. The CVSS v3.1 base score is 5.5, indicating a medium severity. The vector string (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) shows that the attack requires local access (AV:L), low attack complexity (AC:L), and low privileges (PR:L), but no user interaction (UI:N). The impact is high on confidentiality (C:H) but does not affect integrity or availability. There are no known exploits in the wild at the time of publication, and no official patches are linked yet. This vulnerability primarily risks password confidentiality, potentially allowing local attackers or users with limited privileges on the same host to obtain sensitive credentials by inspecting running processes or command histories. This could lead to unauthorized access to source control repositories or further lateral movement within the network if those credentials are reused elsewhere.

For European organizations using JetBrains TeamCity integrated with Mercurial repositories, this vulnerability poses a significant risk to credential confidentiality. Exposure of passwords on the command line can lead to credential theft by malicious insiders or attackers who have gained limited access to build servers. Such credential compromise could allow unauthorized access to source code repositories, potentially leading to intellectual property theft, insertion of malicious code, or disruption of development pipelines. Given that TeamCity is widely used in software development environments across Europe, especially in technology, finance, and manufacturing sectors, the impact could be substantial. Organizations with strict data protection regulations, such as those under GDPR, may face compliance risks if sensitive information is leaked. Additionally, the vulnerability could facilitate further attacks if attackers leverage stolen credentials to escalate privileges or move laterally within corporate networks. The medium CVSS score reflects that while exploitation requires local access and some privileges, the confidentiality impact is high, making it a notable concern for internal security.

1. Immediate mitigation should include restricting local access to build servers running TeamCity to trusted personnel only, minimizing the risk of unauthorized process inspection. 2. Configure TeamCity and Mercurial integrations to avoid passing passwords via command line arguments; instead, use secure credential storage mechanisms such as environment variables, credential helpers, or encrypted configuration files. 3. Monitor and audit process listings and command histories on build servers for any exposure of sensitive information. 4. Implement strict access controls and logging on build infrastructure to detect and respond to suspicious activities promptly. 5. Encourage the use of dedicated service accounts with minimal privileges for build operations to limit potential damage from credential exposure. 6. Once JetBrains releases an official patch or update addressing this vulnerability, prioritize applying it in all affected environments. 7. Educate developers and DevOps teams about the risks of exposing credentials in command lines and promote best practices for secret management. 8. Consider isolating build environments or using containerization to reduce the attack surface for local privilege escalation or credential theft.