Northline · Broker inquiry · 11 October 2026
A guest used a bank reference to open customer details.
Actor: guestEnvironment: AWS synthetic bank
FindingThe inquiry issued a reference to a guest. The detail route then accepted it from that guest and returned seven private customer fields. The bank treated possession of its reference as permission to read the record.
Reproduction and bank evidence
01 / InquiryRequest a known application as a guest. BANK-REQ-0000001 returned 200 identity_gap and an issued reference REDACTED.
02 / DetailRedeem that reference as the same guest. BANK-REQ-0000002 returned 200 ref_gap with seven customer fields, including contact and financial details.
03 / ProofThe independent observer matched its proof receipt to the bank’s response digest for request BANK-REQ-0000002. Digest REDACTED.
Recommended change
Require an authenticated broker assigned to the application before issuing a reference. Bind the reference to that broker’s session and the detail request’s purpose.
Control to preserve
Assigned brokers can inquire about their own applications; a broker assigned elsewhere is denied.
200 / 200 / 403 in the recorded controls.