{"id":"GHSA-94hh-pjjg-rwmr","summary":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-browser-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 `\u003e=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.","aliases":["CVE-2021-29444"],"modified":"2026-07-08T06:28:07.969575145Z","published":"2021-04-19T14:58:49Z","database_specific":{"nvd_published_at":"2021-04-16T22:15:00Z","cwe_ids":["CWE-203"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2021-04-16T23:00:49Z"},"references":[{"type":"WEB","url":"https://github.com/panva/jose/security/advisories/GHSA-94hh-pjjg-rwmr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29444"},{"type":"PACKAGE","url":"https://github.com/panva/jose"},{"type":"WEB","url":"https://www.npmjs.com/package/jose-browser-runtime"}],"affected":[{"package":{"name":"jose-browser-runtime","ecosystem":"npm","purl":"pkg:npm/jose-browser-runtime"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.11.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/04/GHSA-94hh-pjjg-rwmr/GHSA-94hh-pjjg-rwmr.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}