CVE-2025-24459: Medium Vulnerability in JetBrains TeamCity

In JetBrains TeamCity before version 2024.12.1, a reflected Cross-Site Scripting (XSS) vulnerability was identified on the Vault Connection page. This vulnerability allows attackers to inject malicious scripts that can be executed in the context of authenticated users' sessions. The CVSS score for this vulnerability is 4.6, categorizing it as medium severity. This classification highlights the potential impact of such an attack on an organization's security posture.

Risk to organizations includes unauthorized access to sensitive information and manipulation of user sessions, which may lead to further exploitation. Given the nature of XSS attacks, attackers may leverage this vulnerability to perform phishing scams or distribute malware, exploiting trust established with the user. Organizations should prioritize patching immediately.

Currently, there are no known exploits or public proof of concepts available for this vulnerability. However, the potential for exploitation remains, necessitating vigilance among security teams. Organizations using JetBrains TeamCity are advised to monitor their environments closely for any signs of suspicious activity and apply remediation measures as outlined by the vendor.

Remediation for this vulnerability should be addressed in a priority patch cycle, as it can significantly affect the integrity of web applications relying on TeamCity. Organizations are encouraged to review their deployment of JetBrains software and ensure they are operating on the latest patched versions.

Vulnerability Details

The vulnerability is classified as reflected XSS, which is a common web security flaw. It is rated with a CVSS score of 4.6, reflecting its medium severity. The affected product is JetBrains TeamCity, specifically versions prior to 2024.12.1. The vulnerability was published on January 21, 2025, and is associated with CWE-79.

Technical Analysis

The root cause of this vulnerability lies in improper validation and sanitization of user input on the Vault Connection page, which allows untrusted data to be reflected back to users without adequate encoding. The attack vector for this vulnerability is network-based, requiring user interaction to trigger the exploitation.

Attack complexity is classified as low, as attackers can easily craft a malicious link that targets unsuspecting users. The privileges required to exploit this vulnerability are low, as even authenticated users can be affected. User interaction is required to activate the attack, making it imperative for organizations to educate users about the potential risks of clicking on untrusted links.

The impact on confidentiality and integrity is low, but the availability impact is none. This means that while sensitive data may not be directly compromised, attackers can manipulate user sessions and potentially harvest sensitive information.

Risk & Impact Analysis

Organizations using JetBrains TeamCity need to understand the risk associated with this vulnerability. Real-world deployment can expose organizations to significant threats if an attacker successfully exploits the XSS flaw. This vulnerability can serve as a gateway for further attacks, such as session hijacking or data exfiltration, making it critical to address.

The urgency to remediate this vulnerability is heightened by its potential to affect various organizational functions that rely on TeamCity for continuous integration and deployment. Organizations should assess their risk exposure and prioritize this vulnerability within their security patch management processes.

Given the CVSS score of 4.6 and the current absence of known exploits, this vulnerability should still be treated with caution. The potential for exploitation remains, and organizations must stay informed about any emerging threats related to this vulnerability.

Affected Versions

This vulnerability affects all versions of JetBrains TeamCity prior to 2024.12.1. Organizations should ensure they are using the latest version to mitigate this risk.

Mitigation & Remediation

JetBrains has released a patch for this vulnerability in version 2024.12.1. Organizations should update their installations to this version to remediate the vulnerability. If immediate updating is not possible, consider implementing web application firewalls to filter malicious requests, along with proper input validation and sanitation.

Further, organizations are encouraged to maintain continuous security testing and vulnerability assessments to identify and mitigate similar vulnerabilities proactively. For comprehensive security support, organizations may want to explore penetration testing services to enhance their security posture.

Detection Guidance

To detect potential exploitation of this vulnerability, organizations should monitor logs for unusual activities, particularly those involving the Vault Connection page. Look for indicators of XSS attacks, such as unexpected JavaScript execution or unauthorized access attempts.

Additionally, behavioral anomalies in user sessions should be investigated promptly to prevent further exploitation.

AppSecure Threat Intelligence Insight

The presence of this reflected XSS vulnerability in JetBrains TeamCity highlights a broader trend in application security where user input is not adequately validated. Organizations must take lessons from this incident to strengthen input validation across all web applications.

As the cybersecurity landscape evolves, the tactics employed by attackers become increasingly sophisticated. Security teams should consider adopting an offensive security testing approach to proactively identify and remediate security weaknesses.

Organizations are also encouraged to develop a robust vulnerability management program to continuously assess and improve their security posture in response to emerging threats.

In conclusion, security teams must stay informed about vulnerabilities like CVE-2025-24459 and adopt a proactive approach to security that includes regular assessments and timely remediation.