{"id":"CVE-2021-29445","aliases":["GHSA-4v4g-726h-xvfv"],"url":"https://o3.security/vulnerability/CVE-2021-29445","summary":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime","details":"jose-node-esm-runtime is an npm package which provides a number of cryptographic functions. In versions prior to 3.11.4 the AES_CBC_HMAC_SHA2 Algorithm (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). A patch was released which ensures the HMAC tag is verified before performing CBC decryption. The fixed versions are `>=3.11.4`. Users should upgrade to `^3.11.4`.","published":"2021-04-16T22:15:14.060Z","modified":"2026-07-09T11:24:19.605502Z","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":{"score":0.01238,"percentile":0.66342,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"jose-node-esm-runtime","fixedVersion":"3.11.4"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/panva/jose/security/advisories/GHSA-4v4g-726h-xvfv"},{"type":"ADVISORY","url":"https://www.npmjs.com/package/jose-node-esm-runtime"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T11:24:19.605502Z"}}