CVE-2019-0874 in Azure DevOps Server
Summary
by MITRE
A Cross-site Scripting (XSS) vulnerability exists when Azure DevOps Server does not properly sanitize user provided input, aka 'Azure DevOps Server Cross-site Scripting Vulnerability'.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 05/28/2020
The vulnerability identified as CVE-2019-0874 represents a critical cross-site scripting flaw within Azure DevOps Server that stems from inadequate input sanitization mechanisms. This weakness allows malicious actors to inject malicious scripts into web applications that are subsequently executed in the context of other users' browsers. The vulnerability specifically affects the server-side processing of user-provided data within the Azure DevOps environment, creating an attack surface where untrusted input can be manipulated to execute arbitrary code. The flaw resides in the application's failure to properly validate and sanitize user-supplied content before rendering it within web pages, which directly violates fundamental security principles of input validation and output encoding. According to CWE-79, this vulnerability maps to the classic Cross-Site Scripting weakness where improper sanitization of user input leads to execution of malicious scripts in victim browsers. The attack vector typically involves an authenticated user submitting malicious input through various interface elements such as comments, descriptions, or other editable fields within the Azure DevOps platform.
The technical exploitation of this vulnerability requires an attacker to craft malicious payloads that can be stored within the system and subsequently executed when other users view the affected content. This type of vulnerability is particularly dangerous because it leverages the trust relationship between the application and its users, allowing attackers to bypass normal security restrictions. The impact extends beyond simple script execution to potentially enable more sophisticated attacks such as session hijacking, data exfiltration, or privilege escalation within the Azure DevOps environment. Attackers can exploit this weakness to steal session cookies, modify user permissions, or gain unauthorized access to sensitive project information and source code repositories. The vulnerability's persistence in the system means that once exploited, the malicious scripts can continue to execute against all users who interact with the affected content, creating a continuous threat vector that can be difficult to remediate completely. From an operational standpoint, this vulnerability undermines the integrity of the development environment and can compromise the security posture of entire software development lifecycles.
Organizations utilizing Azure DevOps Server must implement comprehensive mitigation strategies to address this vulnerability effectively. The primary remediation involves applying the official Microsoft security patches released to address CVE-2019-0874, which typically include enhanced input validation and output encoding mechanisms. Additionally, implementing proper content security policies and input sanitization routines can significantly reduce the risk of exploitation. Security teams should conduct thorough code reviews to identify potential injection points and ensure that all user-provided content undergoes rigorous validation before processing. The vulnerability aligns with ATT&CK technique T1566 which focuses on credential access through social engineering and malicious payloads. Organizations should also consider implementing web application firewalls and monitoring solutions to detect and prevent exploitation attempts. Regular security assessments and penetration testing can help identify similar vulnerabilities within the broader Azure DevOps ecosystem, while user education about recognizing and reporting suspicious content can serve as an additional defensive layer. The remediation process should include comprehensive testing to ensure that patch implementations do not introduce regressions in functionality while maintaining the security hardening measures.