Oauth2 Proxy
Monthly
Authentication bypass in OAuth2 Proxy versions before 7.15.2 allows remote unauthenticated attackers to access protected resources when deployed with nginx auth_request integration and health check features enabled. Attackers can spoof health check User-Agent headers to bypass OAuth2 authentication entirely, gaining unauthorized access to upstream applications. CVSS 9.1 (Critical) reflects network-accessible, low-complexity attack requiring no privileges or user interaction. No active exploitation confirmed (not in CISA KEV), but the trivial attack complexity and authentication bypass impact warrant immediate patching in affected deployments using nginx auth_request with --ping-user-agent or --gcp-healthchecks flags.
OAuth2 Proxy versions 7.11.0 through 7.15.1 fail to clear the session cookie when rendering the sign-in page due to a regression, allowing authenticated users to remain logged in even after attempting to log out via the sign-in page. On shared workstations, a subsequent user could hijack the previous user's authenticated session without additional credentials. This affects only deployments using the sign-in page as part of logout flow; organizations with dedicated logout endpoints are unaffected. The vulnerability carries a low CVSS score of 3.5 (physical attack vector required) but poses meaningful risk in shared-access environments.
Authentication bypass in OAuth2 Proxy versions before 7.15.2 allows remote unauthenticated attackers to access protected resources when deployed with nginx auth_request integration and health check features enabled. Attackers can spoof health check User-Agent headers to bypass OAuth2 authentication entirely, gaining unauthorized access to upstream applications. CVSS 9.1 (Critical) reflects network-accessible, low-complexity attack requiring no privileges or user interaction. No active exploitation confirmed (not in CISA KEV), but the trivial attack complexity and authentication bypass impact warrant immediate patching in affected deployments using nginx auth_request with --ping-user-agent or --gcp-healthchecks flags.
OAuth2 Proxy versions 7.11.0 through 7.15.1 fail to clear the session cookie when rendering the sign-in page due to a regression, allowing authenticated users to remain logged in even after attempting to log out via the sign-in page. On shared workstations, a subsequent user could hijack the previous user's authenticated session without additional credentials. This affects only deployments using the sign-in page as part of logout flow; organizations with dedicated logout endpoints are unaffected. The vulnerability carries a low CVSS score of 3.5 (physical attack vector required) but poses meaningful risk in shared-access environments.