CVE-2025-12627 in Identity Server
Summary
by MITRE • 08/06/2026
The user impersonation flow in WSO2 Identity Server fails to properly manage refresh tokens associated with impersonated sessions. This allows an attacker who has obtained an access token for an impersonated user to leverage the refresh token grant to obtain new access tokens, extending their ability to act as the legitimate user.
An attacker who gains access to an impersonated user's access token can exploit this weakness to renew their authorization. This results in the continued ability to perform actions on behalf of the actual user, compromising log integrity and traceability by masking the true actor.
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Analysis
by VulDB Data Team • 08/06/2026
The vulnerability described represents a critical authorization flaw in WSO2 Identity Server's user impersonation functionality that directly impacts session management and access control mechanisms. This weakness stems from improper handling of refresh tokens within impersonated user sessions, creating a persistent security gap that allows unauthorized actors to maintain prolonged access to victim accounts. The issue manifests when an attacker successfully obtains an access token for an impersonated user, then leverages the associated refresh token to continuously generate new access tokens without proper authentication checks.
The technical implementation flaw resides in the server's failure to properly validate and manage refresh token lifecycle when user impersonation is involved. Standard OAuth 2.0 protocols typically establish clear boundaries around token usage and refresh mechanisms, but WSO2 Identity Server appears to bypass these security controls during impersonation workflows. This creates a scenario where refresh tokens issued for impersonated sessions retain their validity beyond the intended scope, enabling attackers to extend their unauthorized access indefinitely. The vulnerability directly relates to CWE-613, which addresses inadequate session management and improper handling of authentication tokens that persist beyond their expected lifetime.
From an operational perspective, this vulnerability compromises the fundamental principles of identity and access management by allowing persistent unauthorized access that can go undetected for extended periods. The attack vector enables what security researchers classify as a privilege escalation and persistent access pattern, where initial compromise through token theft leads to prolonged unauthorized activities. The impact extends beyond simple unauthorized access to include complete loss of audit trail integrity, as the system cannot properly distinguish between legitimate user actions and those performed by attackers using stolen tokens. This undermines the traceability mechanisms that organizations rely upon for security monitoring and incident response.
The mitigation strategies should focus on implementing proper refresh token validation within impersonation contexts, ensuring that tokens issued for impersonated sessions are scoped appropriately and expire according to established security policies. Organizations should enforce strict session management controls that prevent refresh token reuse across different authentication contexts, aligning with ATT&CK technique T1566 which addresses credential harvesting and privilege escalation through token manipulation. Additionally, implementing enhanced monitoring for suspicious token renewal patterns and establishing automated alerting for unauthorized impersonation activities would significantly reduce the risk exposure. Security configurations should enforce immediate revocation of refresh tokens when impersonation sessions terminate, and organizations must conduct regular security assessments to identify similar token management vulnerabilities in their identity infrastructure.