High advisory for OpenCSG CSGHub

Advisory overview

OpenCSG CSGHub through v2.6.0-ce contains an authorization bypass vulnerability in the unauthenticated file resolve route that allows remote attackers to read private repository files. Attackers can inject a percent-encoded current_user parameter into the file path, which the portal forwards with its server API key, to read files in private model, code or space repositories.

Related references

• https://github.com/OpenCSGs/csghub-server/blob/v2.6.0-ce/api/middleware/authenticator.go#L210-L226
• https://github.com/OpenCSGs/csghub/blob/v2.6.0-ce/internal/handlers/frontend/resolve.go#L138-L151
• https://github.com/OpenCSGs/csghub/blob/v2.6.0-ce/internal/routes/router.go#L302-L303
• https://github.com/OpenCSGs/csghub/blob/v2.6.0-ce/pkg/server/backend/csghubserver/download.go#L10-L41
• https://github.com/OpenCSGs/csghub/issues/1586
• https://github.com/OpenCSGs/csghub/releases/tag/v2.6.0-ce
• https://hackmd.io/@hieund/csghub-private-repo-file-read-idor
• https://www.vulncheck.com/advisories/opencsg-csghub-through-2.6.0-ce-unauthenticated-private-repository-file-read-via-resolve-route