CVE-2015-1313 in TeamCity
Summary
by MITRE • 06/29/2023
JetBrains TeamCity 8 and 9 before 9.0.2 allows bypass of account-creation restrictions via a crafted request because the required request data can be deduced by reading HTML and JavaScript files that are returned to the web browser after an initial unauthenticated request.
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Analysis
by VulDB Data Team • 07/21/2023
This vulnerability in JetBrains TeamCity versions 8 and 9 before 9.0.2 represents a critical authentication bypass flaw that undermines the software's user management security controls. The vulnerability stems from insufficient validation of account creation requests, allowing malicious actors to circumvent intended access restrictions through careful analysis of the application's response patterns. The flaw specifically exploits the predictable nature of the authentication flow, where attackers can deduce the necessary request parameters by examining the HTML and JavaScript responses returned to browsers during initial unauthenticated interactions.
The technical implementation of this vulnerability demonstrates a classic case of insecure direct object reference combined with insufficient input validation. When TeamCity processes initial unauthenticated requests, it inadvertently exposes the structure and requirements of subsequent authentication endpoints through its response content. This exposure occurs because the application's design does not properly separate the authentication flow logic from the publicly accessible frontend components. Attackers can analyze the JavaScript code and HTML templates to understand the expected parameters for account creation, including field names, validation requirements, and data formats, which then enables them to construct valid requests that bypass the intended access controls.
The operational impact of this vulnerability extends beyond simple unauthorized account creation, potentially allowing attackers to escalate privileges within the TeamCity environment. Since TeamCity serves as a continuous integration and deployment platform, unauthorized access to user accounts can lead to unauthorized code deployments, modification of build configurations, and potential access to sensitive development environments. The vulnerability affects organizations that rely on TeamCity for their software development pipelines, creating risks for intellectual property protection and operational integrity. The fact that this vulnerability exists in widely used versions 8 and 9 means that numerous organizations may be exposed to this risk without proper awareness or mitigation.
Organizations should immediately upgrade to TeamCity version 9.0.2 or later, which contains the necessary patches to address this vulnerability. The fix implemented by JetBrains likely involves strengthening the validation of authentication requests and removing the exposure of internal authentication flow details through frontend responses. Security teams should also implement network-level monitoring to detect unusual authentication patterns and consider additional access controls such as IP whitelisting for authentication endpoints. This vulnerability aligns with CWE-284 (Improper Access Control) and represents a specific implementation weakness that could be categorized under ATT&CK technique T1078 (Valid Accounts) and T1566 (Phishing). Organizations should also review their overall authentication architecture to ensure that sensitive endpoints do not inadvertently expose implementation details that could aid attackers in bypassing security controls.