CVE-2024-42350 — Public key confusion in third party block in Biscuit
Biscuit is an authorization token with decentralized verification, offline attenuation and strong security policy enforcement based on a logic language. Third-party blocks can b…
Published: 2024-08-05 · CVSS: 3.0 · CVSS 3.1
Biscuit is an authorization token with decentralized verification, offline attenuation and strong security policy enforcement based on a logic language. Third-party blocks can be generated without transferring the whole token to the third-party authority. Instead, a `ThirdPartyBlock` request can be sent, providing only the necessary info to generate a third-party block and to sign it: 1. the public key of the previous block (used in the signature), 2. the public keys part of the token symbol table (for public key interning in datalog expressions). A third-part block request forged by a malicious user can trick the third-party authority into generating datalog trusting the wrong keypair. Tokens with third-party blocks containing `trusted` annotations generated through a third party block request. This has been addressed in version 4 of the specification. Users are advised to update their implementations to conform. There are no known workarounds for this vulnerability.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7