{"id":"CVE-2024-41948","aliases":["GHSA-5hcj-rwm6-xmw4"],"url":"https://o3.security/vulnerability/CVE-2024-41948","summary":"biscuit-java vulnerable to public key confusion in third party block","details":"### Impact\nTokens with third-party blocks containing trusted annotations generated through a third party block request. Due to implementation issues in biscuit-java,  third party block support in published versions is inoperating. Nevertheless, to synchronize with other implementations, we publish this advisory and the related fix.\n\n### Description\nThird-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:\n\nthe public key of the previous block (used in the signature)\nthe public keys part of the token symbol table (for public key interning in datalog expressions)\nA third-part block request forged by a malicious user can trick the third-party authority into generating datalog trusting the wrong keypair.\n\nConsider the following example (nominal case)\n* Authority A emits the following token: `check if thirdparty(\"b\") trusting ${pubkeyB}`\n* The well-behaving holder then generates a third-party block request based on the token and sends it to third-party authority B\n* Third-party B generates the following third-party block `thirdparty(\"b\"); check if thirdparty(\"c\") trusting ${pubkeyC}`\n* The token holder now must obtain a third-party block from third party C to be able to use the token\n\nNow, with a malicious user:\n* Authority A emits the following token: `check if thirdparty(\"b\") trusting ${pubkeyB}`\n* The holder then attenuates the token with the following third party block `thirdparty(\"c\")`, signed with a keypair pubkeyD, privkeyD) they generate\n* The holder then generates a third-party block request based on this token, but alter the `ThirdPartyBlockRequest` publicKeys field and replace pubkeyD with pubkeyC\n* Third-party B generates the following third-party block `thirdparty(\"b\"); check if thirdparty(\"c\") trusting ${pubkeyC}`\n* Due to the altered symbol table, the actual meaning of the block is `thirdparty(\"b\"); check if thirdparty(\"c\") trusting ${pubkeyD}`\n* The attacker can now use the token without obtaining a third-party block from C.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\n### References\n_Are there any links users can visit to find out more?_\n\n","published":"2024-08-01T22:03:15.788Z","modified":"2026-08-27T03:57:03.067435540Z","cvss":{"score":3,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.biscuitsec:biscuit","fixedVersion":"4.0.0"}],"fix":{"url":"https://github.com/biscuit-auth/biscuit-java/commit/2e05e7b3f8f2aae38f33294f19419e2d638cb564","label":"biscuit-auth/biscuit-java@2e05e7b"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/41xxx/CVE-2024-41948.json"},{"type":"ADVISORY","url":"https://github.com/biscuit-auth/biscuit-java/security/advisories/GHSA-5hcj-rwm6-xmw4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-41948"},{"type":"WEB","url":"https://github.com/biscuit-auth/biscuit/security/advisories/GHSA-rgqv-mwc3-c78m"},{"type":"WEB","url":"https://github.com/biscuit-auth/biscuit-java/commit/2e05e7b3f8f2aae38f33294f19419e2d638cb564"},{"type":"PACKAGE","url":"https://github.com/biscuit-auth/biscuit-java"},{"type":"WEB","url":"https://github.com/biscuit-auth/biscuit-java/releases/tag/4.0.0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T03:57:03.067435540Z"}}