{"id":"CVE-2021-29446","aliases":["GHSA-rvcw-f68w-8h8h"],"url":"https://o3.security/vulnerability/CVE-2021-29446","summary":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-cjs-runtime","details":"### Impact\n\n[AES_CBC_HMAC_SHA2 Algorithm](https://tools.ietf.org/html/rfc7518#section-5.2) (A128CBC-HS256, A192CBC-HS384, A256CBC-HS512) decryption would always execute both HMAC tag verification and CBC decryption, if either failed `JWEDecryptionFailed` would be thrown. But a possibly observable difference in timing when padding error would occur while decrypting the ciphertext makes a padding oracle and an adversary might be able to make use of that oracle to decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block).\n\n### Patches\n\nA patch was released which ensures the HMAC tag is verified before performing CBC decryption. The fixed versions are `>=3.11.4`.\n\nUsers should upgrade to `^3.11.4`.\n\n### Credits\nThanks to Morgan Brown of Microsoft for bringing this up and Eva Sarafianou (@esarafianou) for helping to score this advisory.","published":"2021-04-16T22:15:14.140Z","modified":"2026-07-09T02:49:38.868204Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"jose-node-cjs-runtime","fixedVersion":"3.11.4"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/panva/jose/security/advisories/GHSA-rvcw-f68w-8h8h"},{"type":"ADVISORY","url":"https://www.npmjs.com/package/jose-node-cjs-runtime"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29446"},{"type":"PACKAGE","url":"https://github.com/panva/jose"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T02:49:38.868204Z"}}