CVE-2026-58273: High severity pip/rucio vulnerability

Summary The /credentials/signurl endpoint decides authorization from the client-supplied X-Rucio-Account HTTP header instead of the authenticated token's account. Any client holding any valid auth token (even a low-privilege account they legitimately own) can send X-Rucio-Account: root to pass the root-only permission check and have the Rucio server mint a presigned read / write / delete URL for an arbitrary object, signed with the RSE's stored S3 / GCS / Swift credentials.

Details SignURL.get() takes the authorization principal from a request header and never uses the token-authenticated identity:

python lib/rucio/web/rest/flaskapi/v1/credentials.py account = request.headers.get('X-Rucio-Account', default=None) # L165 (attacker-controlled) ... result = getsignedurl(account, rse=rse, service=service, # L194 operation=operation, url=url, lifetime=lifetime, vo=vo)

The gateway then uses that header value as the issuer for the permission check:

python lib/rucio/gateway/credential.py authresult = permission.haspermission(issuer=account, vo=vo, # L57 action='getsignedurl', kwargs=kwargs, ...)

and the permission function is root-only:

python lib/rucio/core/permission/generic.py def permgetsignedurl(issuer, kwargs, session): return isroot(issuer) # isroot(x) -> x.external == 'root'

InternalAccount('root', vo).external == 'root' unconditionally, so the gate passes whenever the header is root. The endpoint is on AuthenticatedBlueprint, whose beforerequest hook validates the token and sets request.environ['issuer'] from the token — but nothing ever compares X-Rucio-Account to it:

python lib/rucio/web/rest/flaskapi/v1/common.py (requestauthenv) flask.request.environ['issuer'] = auth.get('account') # L168 (the real account; unused by SignURL)

This is anomalous: every other authenticated handler derives the account from request.environ['issuer']; credentials.py is the only one that trusts the header. Additionally, core.credential.getsignedurl never checks that the supplied url's host/bucket belongs to the target RSE, so even a legitimate root caller gets an arbitrary-object signing oracle. In multi-VO the VO is also read from the X-Rucio-VO header, allowing cross-tenant targeting.

Proof of concept Request (any valid token + spoofed account): GET /credentials/signurl?rse=<cloudRSE>&svc=s3&op=delete&url=https://victim-bucket.s3.amazonaws.com/important/dataset.root HTTP/1.1 X-Rucio-Auth-Token: <any valid token, even a low-privilege account> X-Rucio-Account: root Accept: application/octet-stream Response: 200 OK with a presigned DELETE URL the attacker replays directly against the storage backend.

Impact A low-privilege Rucio user can read, overwrite, and delete arbitrary objects on any cloud-backed (S3/GCS/Swift) RSE using the server's stored credentials — enabling data exfiltration, tampering, and destruction, and cross-tenant access in multi-VO deployments.

Credit Reported by seankohjs. Found via static analysis + manual verification.