CVE-2025-54528 is a Cross-Site Request Forgery (CSRF) vulnerability identified in JetBrains TeamCity, a popular continuous integration and build management system widely used in software development environments. The vulnerability affects versions of TeamCity prior to 2025.07 and specifically targets the GitHub App connection flow. CSRF vulnerabilities allow an attacker to trick an authenticated user into submitting a forged HTTP request to a web application, potentially causing unauthorized actions to be performed on behalf of the user without their consent. In this case, the flaw lies in insufficient protection against CSRF attacks during the GitHub App integration process, which could allow an attacker to manipulate or alter the connection settings between TeamCity and GitHub repositories. The CVSS v3.1 base score for this vulnerability is 5.4, indicating a medium severity level. The vector string (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N) shows that the attack can be performed remotely over the network with low attack complexity, requires no privileges, but does require user interaction. The impact affects confidentiality and integrity to a limited extent but does not affect availability. No known exploits are currently reported in the wild, and no official patches or mitigation links are provided yet. The vulnerability is classified under CWE-352, which corresponds to CSRF attacks. Given the nature of TeamCity as a CI/CD tool, exploitation could lead to unauthorized changes in build configurations or repository connections, potentially undermining the integrity of the software development lifecycle and introducing risks such as unauthorized code changes or pipeline disruptions.

For European organizations, the impact of CVE-2025-54528 could be significant, especially for those heavily reliant on automated build and deployment pipelines using JetBrains TeamCity integrated with GitHub repositories. Unauthorized manipulation of the GitHub App connection flow could allow attackers to alter repository access or build configurations, potentially injecting malicious code or disrupting continuous integration processes. This could lead to compromised software integrity, delayed development cycles, and increased risk of supply chain attacks. Organizations in sectors with high regulatory requirements, such as finance, healthcare, and critical infrastructure, may face compliance issues if unauthorized changes go undetected. Additionally, the medium severity and requirement for user interaction mean that phishing or social engineering campaigns could be used to exploit this vulnerability, increasing the risk profile. Although no active exploits are known, the widespread use of TeamCity in European software development environments makes this a relevant threat that should be addressed promptly to maintain secure development operations.

To mitigate CVE-2025-54528, European organizations should take the following specific actions: 1) Immediately upgrade TeamCity to version 2025.07 or later once the patch is officially released by JetBrains to ensure the CSRF vulnerability is remediated. 2) Until a patch is available, implement strict network segmentation and access controls to limit exposure of the TeamCity server, especially restricting access to trusted IP ranges and enforcing strong authentication mechanisms. 3) Educate users and developers about the risk of phishing and social engineering attacks that could trigger CSRF exploits, emphasizing caution when interacting with unexpected links or prompts related to GitHub integrations. 4) Review and audit existing GitHub App connections within TeamCity for any unauthorized changes or suspicious activity, and consider temporarily disabling GitHub App integrations if feasible. 5) Employ Web Application Firewalls (WAFs) with CSRF protection rules to detect and block suspicious requests targeting the TeamCity GitHub App connection endpoints. 6) Monitor logs and alerts for unusual activity related to build configurations or repository access changes to enable rapid incident response. These targeted measures go beyond generic advice by focusing on the specific integration flow and operational context of TeamCity in European environments.