Overview
On May 8, 2025, Microsoft disclosed CVE-2025-29813, a critical elevation of privilege vulnerability affecting Azure DevOps Server. The vulnerability has been assigned a maximum CVSS score of 10.0, indicating its severity and potential impact. This flaw allows an unauthorized attacker to gain elevated privileges over a network through an authentication bypass mechanism.
Technical Details
The vulnerability is categorized under CWE-302: Authentication Bypass by Assumed-Immutable Data. This class of vulnerability arises when systems trust data that is presumed immutable—such as identity claims or tokens—without adequate verification. In the context of Azure DevOps Server, the system failed to validate these identity claims properly, enabling attackers to spoof identities and escalate their privileges.
The root cause lies in the handling of spoofable identity claims. Attackers who can craft these claims and inject them into a session may assume elevated roles or access levels that should not be available to them. Since the vulnerability is network-exploitable and does not require user interaction or prior authentication, it significantly raises the risk profile.
What Is CVSS 3.1?
The Common Vulnerability Scoring System (CVSS) provides a standardized method for rating the severity of security vulnerabilities. In this case, the vulnerability scored 10.0 (CRITICAL) under CVSS 3.1. The vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H breaks down as follows:
- AV:N – Attack vector is network-based
- AC:L – Low attack complexity
- PR:N – No privileges required
- UI:N – No user interaction
- S:C – Scope change occurs
- C:H/I:H/A:H – High impact on confidentiality, integrity, and availability
These factors combine to reflect a worst-case scenario for enterprise environments relying on Azure DevOps Server.
Impacted Systems
The vulnerability affects all versions of Microsoft Azure DevOps Server as no specific version was excluded in the disclosure. This includes self-hosted installations that may not benefit from automatic security patches.
Recommended Mitigations
- Apply official patches or updates released by Microsoft as soon as they become available.
- Audit identity and access management policies to detect unusual privilege escalations.
- Monitor network traffic for signs of spoofed identity tokens.
- Restrict access to Azure DevOps interfaces from untrusted networks.
Conclusion
CVE-2025-29813 exemplifies the critical risks posed by improperly validated authentication data. Enterprises using Azure DevOps Server must act swiftly to mitigate this vulnerability and reinforce trust boundaries in their identity systems.
For more details, see Microsoft’s official advisory: CVE-2025-29813.
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