CVE-2025-29813 is a critical authentication bypass vulnerability identified in Microsoft Azure DevOps, classified under CWE-302 (Authentication Bypass by Assumed-Immutable Data). This vulnerability arises from the system's incorrect assumption that certain identity claims or authentication data are immutable and trustworthy. An attacker exploiting this flaw can spoof identity claims over the network, effectively bypassing authentication controls without requiring any privileges or user interaction. The vulnerability has a CVSS 3.1 base score of 10.0, indicating maximum severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), allowing an attacker to fully compromise Azure DevOps environments. Given Azure DevOps' role in software development lifecycle management, this vulnerability could enable attackers to elevate privileges, manipulate source code repositories, alter build pipelines, or disrupt deployment processes, potentially leading to widespread compromise of software supply chains and intellectual property theft. Although no known exploits are currently reported in the wild, the critical nature and ease of exploitation make this a significant threat requiring immediate attention.

For European organizations, the impact of CVE-2025-29813 is substantial due to the widespread adoption of Microsoft Azure DevOps in software development and IT operations. Exploitation could lead to unauthorized access to sensitive codebases, build configurations, and deployment pipelines, resulting in intellectual property theft, insertion of malicious code, and disruption of critical business applications. This can undermine trust in software integrity and availability, affecting sectors reliant on continuous integration and continuous deployment (CI/CD) such as finance, healthcare, telecommunications, and government services. Additionally, compromised Azure DevOps environments could serve as a pivot point for broader network intrusions, data breaches, or ransomware attacks. The vulnerability's network-based exploitation and lack of required privileges or user interaction increase the risk of rapid and widespread attacks across European enterprises, potentially impacting supply chain security and regulatory compliance obligations such as GDPR.

To mitigate CVE-2025-29813, European organizations should immediately prioritize the deployment of any patches or updates released by Microsoft for Azure DevOps. In the absence of available patches, organizations should implement network-level controls such as restricting access to Azure DevOps services via IP whitelisting and enforcing strict network segmentation to limit exposure. Employ multi-factor authentication (MFA) for all Azure DevOps accounts to add an additional layer of verification, even though the vulnerability bypasses authentication, as this may help reduce risk from other attack vectors. Conduct thorough audits of identity claims and tokens used within Azure DevOps environments to detect anomalies or suspicious modifications. Monitor logs and alerts for unusual authentication patterns or privilege escalations. Additionally, consider implementing just-in-time access and least privilege principles to minimize the impact of any successful exploitation. Organizations should also review and strengthen their software supply chain security practices, including code signing and integrity verification, to detect unauthorized changes resulting from exploitation.