{"items":[{"id":"NVI-00014021","kind":"vulnerability","title":"rclone serve s3: --auth-proxy without --auth-key authenticates nobody - full SigV4 signature bypass","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-xwwr-4h3p-r22c","CVE-2026-88018"],"plain_summary":"GitHub lists this reviewed advisory for github.com/rclone/rclone. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-32e75ca43a03e88687cb4e9c453166b2"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-09-10T22:49:08.000Z","value":"9.8 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-32e75ca43a03e88687cb4e9c453166b2"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-32e75ca43a03e88687cb4e9c453166b2","url":"https://github.com/advisories/GHSA-xwwr-4h3p-r22c","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-xwwr-4h3p-r22c","publisher":"GitHub Advisory Database","observed_at":"2026-11-01T22:54:05.264Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-32e75ca43a03e88687cb4e9c453166b2"],"technology":"github.com/rclone/rclone","known_exclusions":[],"conditions_summary":"### Summary\n`rclone serve s3`'s handler chain, when `--auth-proxy` is configured, is (outermost first): `authPairMiddleware` -> `proxyAuthMiddleware` -> gofakes3's own SigV4-verifying handler.\n\n`authPairMiddleware` parses the accessKeyID straight out of the incoming request's own `Authorization` header (entirely client-controlled) and registers `{accessKey: ws.s3Secret}` into gofakes3's shared credential store via `AddAuthKeys`, for EVERY access key any client presents - not just ones previously known to the server. `ws.s3Secret` defaults to `\"\"` whenever `--auth-key` is not set, which the `--auth-proxy` documentation (and the reference `bin/test_proxy.py`) presents as a complete, standalone authentication mechanism requiring no other flag - matching how it's used for `serve webdav`/`ftp`/`sftp`.\n\ngofakes3's SigV4 verification then checks the request's signature against exactly the secret `authPairMiddleware` just registered for that same client-chosen key. An empty string is a valid HMAC key, so a caller can trivially compute a correct SigV4 signature for ANY access key ID of their choosing using an empty secret, and verification passes.\n\nCrucially, the auth-proxy script never rec","public_affected_ranges":["< 1.75.1"]}],"null_published_at":"2026-11-02T10:00:37.197Z","source_updated_at":"2026-09-10T22:49:08.000Z","source_disclosed_at":"2026-09-10T22:49:07.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-01T22:54:05.264Z"}],"next_cursor":null,"snapshot_revision":"39771"}