Bug 2385267 (CVE-2025-54576)

Summary: CVE-2025-54576 github.com/oauth2-proxy/oauth2-proxy: OAuth2-Proxy authentication bypass
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: amctagga, aoconnor, bniver, flucifre, gmeno, mbenjamin, mhackett, sostapov, vereddy
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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An authentication bypass flaw was found in the OAuth2-Proxy project. This bypass affects systems that have configured their deployment to skip authentication on endpoints that match a deployment-defined regular expression. HTTP parameters can be used to match and trigger the authentication bypass in unexpected ways.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2385282    
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Description OSIDB Bzimport 2025-07-30 20:01:08 UTC 
OAuth2-Proxy is an open-source tool that can act as either a standalone reverse proxy or a middleware component integrated into existing reverse proxy or load balancer setups. In versions 7.10.0 and below, oauth2-proxy deployments are vulnerable when using the skip_auth_routes configuration option with regex patterns. Attackers can bypass authentication by crafting URLs with query parameters that satisfy configured regex patterns, allowing unauthorized access to protected resources. The issue stems from skip_auth_routes matching against the full request URI. Deployments using skip_auth_routes with regex patterns containing wildcards or broad matching patterns are most at risk. This issue is fixed in version 7.11.0. Workarounds include: auditing all skip_auth_routes configurations for overly permissive patterns, replacing wildcard patterns with exact path matches where possible, ensuring regex patterns are properly anchored (starting with ^ and ending with $), or implementing custom validation that strips query parameters before regex matching.