Headline

GHSA-652x-m2gr-hppm: OAuth2-Proxy's `--gitlab-group` GitLab Group Authorization config flag stopped working in v7.0.0

The --gitlab-group flag for group-based authorization in the GitLab provider stopped working in the v7.0.0 release.

Regardless of the flag settings, authorization wasn’t restricted. Additionally, any authenticated users had whichever groups were set in --gitlab-group added to the new X-Forwarded-Groups header to the upstream application.

While adding GitLab project based authorization support in #630, a bug was introduced where the user session’s groups field was populated with the --gitlab-group config entries instead of pulling the individual user’s group membership from the GitLab Userinfo endpoint. When the session groups where compared against the allowed groups for authorization, they matched improperly (since both lists were populated with the same data) so authorization was allowed.

Impact

This impacts GitLab Provider users who relies on group membership for authorization restrictions. Any authenticated users in your GitLab environment can access your applications regardless of --gitlab-group membership restrictions.

Patches

This is patched in v7.1.0

Workarounds

There is no workaround for the Group membership bug. But --gitlab-project can be set to use Project membership as the authorization checks instead of groups; it is not broken.

18 days ago

ghsa

Open in Source

#git #perl #oauth #auth

The --gitlab-group flag for group-based authorization in the GitLab provider stopped working in the v7.0.0 release.

Regardless of the flag settings, authorization wasn’t restricted. Additionally, any authenticated users had whichever groups were set in --gitlab-group added to the new X-Forwarded-Groups header to the upstream application.

While adding GitLab project based authorization support in #630, a bug was introduced where the user session’s groups field was populated with the --gitlab-group config entries instead of pulling the individual user’s group membership from the GitLab Userinfo endpoint. When the session groups where compared against the allowed groups for authorization, they matched improperly (since both lists were populated with the same data) so authorization was allowed.

Impact

Patches

This is patched in v7.1.0

Workarounds

There is no workaround for the Group membership bug. But --gitlab-project can be set to use Project membership as the authorization checks instead of groups; it is not broken.

References