CVE-2019-0866 in Azure DevOps Server
Summary
by MITRE
A Cross-site Scripting (XSS) vulnerability exists when Azure DevOps Server and Team Foundation Server do not properly sanitize user provided input, aka 'Azure DevOps Server and Team Foundation Server Cross-site Scripting Vulnerability'. This CVE ID is unique from CVE-2019-0867, CVE-2019-0868, CVE-2019-0870, CVE-2019-0871.
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Analysis
by VulDB Data Team • 08/28/2023
The vulnerability described in CVE-2019-0866 represents a critical cross-site scripting flaw affecting Azure DevOps Server and Team Foundation Server versions prior to the security updates. This issue stems from insufficient input validation mechanisms that fail to properly sanitize user-provided data before processing or rendering within the web application interface. The flaw exists in the core web application components responsible for handling user interactions and data display, creating a persistent vector for malicious code injection attacks that can compromise user sessions and data integrity.
The technical implementation of this vulnerability occurs when the affected systems process user input through web forms, comments, or other interactive elements without adequate sanitization of potentially malicious payloads. Attackers can craft specially formatted input containing javascript code or other malicious scripts that get executed in the context of other users' browsers when they view the compromised content. This type of vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically representing a stored XSS variant where malicious code is permanently stored on the server and executed whenever users access the affected content. The vulnerability's impact is amplified by the privileged nature of Azure DevOps Server environments, where users typically possess elevated access rights to development resources and sensitive project data.
The operational implications of this vulnerability extend beyond simple data theft or session hijacking, as it can enable attackers to manipulate the development workflow, access confidential source code repositories, modify project configurations, or even inject malicious code into legitimate applications. The attack surface is particularly concerning in enterprise environments where Azure DevOps Server serves as a central hub for software development collaboration, making it a prime target for attackers seeking persistent access to development infrastructure. The vulnerability affects both authenticated and unauthenticated users, though the severity increases significantly when attackers can leverage legitimate user accounts to execute malicious payloads with elevated privileges.
Mitigation strategies for this vulnerability should include immediate application of Microsoft security patches and updates specifically addressing the XSS flaw in Azure DevOps Server and Team Foundation Server. Organizations must implement comprehensive input validation mechanisms that sanitize all user-provided content using established security libraries and frameworks. Network segmentation and web application firewalls can provide additional defense-in-depth layers to detect and block suspicious traffic patterns. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in the broader application ecosystem. The ATT&CK framework categorizes this vulnerability under T1059.007 for Scripting and T1566 for Phishing, highlighting the need for both technical controls and user awareness training to prevent exploitation. Organizations should also implement proper access controls and monitoring mechanisms to detect anomalous user behavior that might indicate exploitation attempts.