CVE-2021-32701
When caching is disabled, this vulnerability does not exist.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.63%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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(...)`](https://github.com/ory/oathkeeper/blob/6a31df1c3779425e05db1c2a381166b087cb29a4/pipeline/authn/authenticator_oauth2_introspection.go#L152). From [`tokenFromCache()`](https://github.com/ory/oathkeeper/blob/6a31df1c3779425e05db1c2a381166b087cb29a4/pipeline/authn/authenticator_oauth2_introspection.go#L97) 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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 1.63% probability · 75th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Affected
- ory/oathkeeper
- Source
- security-advisories@github.com
References
- https://github.com/ory/oathkeeper/commit/1f9f625c1a49e134ae2299ee95b8cf158feec932Patch, Third Party Advisory
- https://github.com/ory/oathkeeper/pull/424Patch, Third Party Advisory
- https://github.com/ory/oathkeeper/security/advisories/GHSA-qvp4-rpmr-xwrrThird Party Advisory
- https://github.com/ory/oathkeeper/commit/1f9f625c1a49e134ae2299ee95b8cf158feec932Patch, Third Party Advisory
- https://github.com/ory/oathkeeper/pull/424Patch, Third Party Advisory
- https://github.com/ory/oathkeeper/security/advisories/GHSA-qvp4-rpmr-xwrrThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.