Summary
Unauthenticated user can access credentials of last authenticated user via OpenID or OAuth2 where the authentication URL did not include redirect query string.
For example:
- Project is configured with OpenID or OAuth2
- Project is configured with cache enabled
- User tries to login via SSO link, but without
redirect query string
- After successful login, credentials are cached
- If an unauthenticated user tries to login via SSO link, it will return the credentials of the other last user
The SSO link is something like https://directus.example.com/auth/login/openid/callback, where openid is the name of the OpenID provider configured in Directus
Details
This happens because on that endpoint for both OpenId and Oauth2 Directus is using the respond middleware, which by default will try to cache GET requests that met some conditions. Although, those conditions do not include this scenario, when an unauthenticated request returns user credentials.
For OpenID, this can be seen here:
https://github.com/directus/directus/blob/main/api/src/auth/drivers/openid.ts#L453-L459
And for OAuth2 can be seen here
https://github.com/directus/directus/blob/main/api/src/auth/drivers/oauth2.ts#L422-L428
PoC
- Create a new Directus project
- Set
CACHE_ENABLED to true
- Set
CACHE_STORE to redis for reliable results (if using memory with multiple nodes, it may only happen sometimes, due to cache being different for different nodes)
- Configure
REDIS with redis string or redis host, port, user, etc.
- Set
AUTH_PROVIDERS to openid
- Set
PUBLIC_URL to the the main URL of your project . For example, PUBLIC_URL: http://localhost:8055
- Configure
AUTH_OPENID_CLIENT_ID, AUTH_OPENID_CLIENT_SECRET, AUTH_OPENID_ISSUER_URL with proper OpenID configurations
- Be sure that on OpenID external app you have configured Redirect URI to
http://localhost:8055/auth/login/openid/callback
- Run Directus
- Open the SSO link like
http://localhost:8055/auth/login/openid/callback
- Do the authentication on the OpenID external webpage
- Verify that it you got redirected to a page with a JSON including
access_token property
- Be sure all anonymous mode windows are closed
- Open an anonymous window and go to the SSO Link
http://localhost:8055/auth/login/openid/callback and see you have the same credentials, even though you don't have any session because you are in anonymous mode
Impact
All projects using OpenID or OAuth 2, that does not include redirect query string on loggin in users.
References
Summary
Unauthenticated user can access credentials of last authenticated user via OpenID or OAuth2 where the authentication URL did not include
redirectquery string.For example:
redirectquery stringThe SSO link is something like
https://directus.example.com/auth/login/openid/callback, whereopenidis the name of the OpenID provider configured in DirectusDetails
This happens because on that endpoint for both OpenId and Oauth2 Directus is using the
respondmiddleware, which by default will try to cache GET requests that met some conditions. Although, those conditions do not include this scenario, when an unauthenticated request returns user credentials.For OpenID, this can be seen here:
https://github.com/directus/directus/blob/main/api/src/auth/drivers/openid.ts#L453-L459
And for OAuth2 can be seen here
https://github.com/directus/directus/blob/main/api/src/auth/drivers/oauth2.ts#L422-L428
PoC
CACHE_ENABLEDto trueCACHE_STOREtoredisfor reliable results (if using memory with multiple nodes, it may only happen sometimes, due to cache being different for different nodes)REDISwith redis string or redis host, port, user, etc.AUTH_PROVIDERStoopenidPUBLIC_URLto the the main URL of your project . For example,PUBLIC_URL: http://localhost:8055AUTH_OPENID_CLIENT_ID,AUTH_OPENID_CLIENT_SECRET,AUTH_OPENID_ISSUER_URLwith proper OpenID configurationshttp://localhost:8055/auth/login/openid/callbackhttp://localhost:8055/auth/login/openid/callbackaccess_tokenpropertyhttp://localhost:8055/auth/login/openid/callbackand see you have the same credentials, even though you don't have any session because you are in anonymous modeImpact
All projects using OpenID or OAuth 2, that does not include
redirectquery string on loggin in users.References