CVE-2025-54535: JetBrains TeamCity Info Disclosure Flaw

CVE-2025-54535 Overview

CVE-2025-54535 affects JetBrains TeamCity versions prior to 2025.07. The vulnerability stems from the use of weak hashing algorithms to generate password reset and email verification tokens. An attacker with network access can potentially predict or brute-force these tokens, leading to unauthorized account access. The flaw is classified under CWE-328: Use of Weak Hash. The vulnerability impacts confidentiality but does not directly affect integrity or availability of the system.

Critical Impact
Weak token hashing in JetBrains TeamCity allows attackers to potentially compromise user accounts through predictable password reset tokens, enabling unauthorized access to continuous integration pipelines and source code.

Affected Products

JetBrains TeamCity versions before 2025.07
All TeamCity deployments using built-in password reset functionality
TeamCity instances with email verification enabled

Discovery Timeline

2025-07-28 - CVE-2025-54535 published to NVD
2025-07-29 - Last updated in NVD database

Technical Details for CVE-2025-54535

Vulnerability Analysis

The vulnerability resides in the token generation mechanism for password reset and email verification workflows in JetBrains TeamCity. The application relies on weak hashing algorithms that produce tokens with insufficient entropy or computational resistance against brute-force attempts.

Weak hash functions such as MD5 or unsalted SHA-1 are unsuitable for security-sensitive tokens. When such algorithms protect password reset tokens, attackers can precompute hashes or exploit collision properties to predict valid tokens. This enables account takeover without knowledge of the legitimate user's password.

The attack requires no authentication and no user interaction, as it targets the public-facing password reset workflow. The scope is limited to confidentiality, since successful exploitation results in unauthorized account access rather than direct integrity or availability impact.

Root Cause

The root cause is improper selection of cryptographic primitives [CWE-328]. The application generated security-critical tokens using a hashing algorithm not designed for the threat model. Secure token generation requires cryptographically secure pseudorandom number generators (CSPRNG) combined with strong, salted hash functions or direct random byte generation.

Attack Vector

An unauthenticated remote attacker initiates a password reset request for a target account. The attacker then attempts to predict or brute-force the resulting token by exploiting weaknesses in the underlying hash algorithm. If successful, the attacker uses the predicted token to complete the reset workflow and gain control of the targeted TeamCity account.

No public proof-of-concept exploit code is currently available for this vulnerability. The EPSS probability remains very low at the time of publication. Refer to the JetBrains Security Issues Fixed advisory for vendor technical details.

Detection Methods for CVE-2025-54535

Indicators of Compromise

Unusual volumes of password reset requests targeting privileged TeamCity accounts
Successful password resets followed by configuration changes or build pipeline modifications
Authentication events from unexpected geolocations following reset workflows
Multiple failed token validation attempts in TeamCity server logs

Detection Strategies

Monitor TeamCity audit logs for password reset and email verification token validation events
Correlate reset request patterns with subsequent successful logins from new IP addresses
Inspect web access logs for rapid sequential requests to reset endpoints with varying token values
Establish baselines for normal password reset frequency and alert on deviations

Monitoring Recommendations

Forward TeamCity application and access logs to a centralized SIEM for correlation
Implement rate limiting and alerting on the password reset endpoint
Track administrative actions performed within short windows following password resets
Review user session creation events for anomalous patterns tied to recently reset accounts

How to Mitigate CVE-2025-54535

Immediate Actions Required

Upgrade JetBrains TeamCity to version 2025.07 or later as the primary remediation
Audit recent password reset and email verification events for suspicious activity
Force password resets for privileged accounts and rotate any potentially exposed credentials
Review TeamCity user accounts and remove inactive or unnecessary privileged users

Patch Information

JetBrains released the fix in TeamCity 2025.07. The vendor strengthened the token generation logic to use cryptographically secure algorithms suitable for password reset and email verification workflows. Refer to the JetBrains Security Issues Fixed page for the official advisory and release notes.

Workarounds

Restrict network access to the TeamCity web interface using firewall rules or VPN-only access
Disable self-service password reset functionality and require administrator-initiated resets until patching is complete
Enforce multi-factor authentication (MFA) for all TeamCity accounts to limit the impact of token compromise
Implement strict rate limiting on the password reset endpoint at a reverse proxy or web application firewall

bash

# Example nginx rate limit for TeamCity reset endpoint
limit_req_zone $binary_remote_addr zone=reset_limit:10m rate=5r/m;

location /resetPassword.html {
    limit_req zone=reset_limit burst=3 nodelay;
    proxy_pass http://teamcity_backend;
}