Possible bypass of token claim validation when OAuth2 Introspection caching is enabled

Summary

ORY Oathkeeper is an Identity & Access Proxy (IAP) and Access Control Decision API that authorizes HTTP requests based on sets of Access Rules. When you make a request to an endpoint that requires the scope `foo` using an access token granted with that `foo` scope, introspection will be valid and that token will be cached. The problem comes when a second requests to an endpoint that requires the scope `bar` is made before the cache has expired. Whether the token is granted or not to the `bar` scope, introspection will be valid. A patch will be released with `v0.38.12-beta.1`. Per default, caching is disabled for the `oauth2_introspection` authenticator. When caching is disabled, this vulnerability does not exist. The cache is checked in `func (a *AuthenticatorOAuth2Introspection) Authenticate(...)`. From `tokenFromCache()` it seems that it only validates the token expiration date, but ignores whether the token has or not the proper scopes. The vulnerability was introduced in PR #424. During review, we failed to require appropriate test coverage by the submitter which is the primary reason that the vulnerability passed the review process.

Timeline

1. Jun 22, 2021, 7:45 PM UTCCVE published
2. Aug 3, 2024, 11:25 PM UTCRecord last updated

Affected versions

• ory oathkeeper

  From v0.38.0-beta.2 · fixed in v0.38.12-beta.1

• github.com/ory/oathkeeperGo

  From 0.38.0-beta.2 · fixed in 0.38.12-beta.1

References 3