Json Web Key Set disclosed
Summary: A JSON Web Key Set is a JSON object holding JSON Web Keys, defined in RFC 7517, that authorization servers often publish at well-known URLs so clients can verify the signatures of issued JWTs. PortSwigger Research notes that a misconfigured server may expose private key components alongside public ones, letting a malicious user tamper with JWT signatures and impersonate other users, while exposed public keys alone can still enable attacks such as algorithm and key confusion.
Key Takeaway: A single misconfigured JWK Set can hand an attacker the private keys needed to forge tokens and impersonate any user, and even a public-only set gives them the raw material for algorithm and key confusion attacks.
Read the original at PortSwigger Research ↗
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