{"id":"CVE-2021-29445","aliases":["EUVD-2021-0760","GHSA-4v4g-726h-xvfv"],"status":"published","title":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime","description":"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 `\u003e=3.11.4`. Users should upgrade to `^3.11.4`.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01067,"percentile":0.65074,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-203","CWE-208","CWE-696"],"published":"2021-04-16T21:50:13Z","modified":"2026-10-20T10:53:44Z","fixes":[{"ecosystem":"npm","package":"jose-node-esm-runtime","fixed_in":["3.11.4"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"jose-node-esm-runtime","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.11.4"}]}]},{"source":"osv","ecosystem":"npm","package":"jose-node-esm-runtime","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.11.4"}]}]}],"products":[{"vendor":"jose-node-cjs-runtime_project","product":"jose-node-cjs-runtime"},{"vendor":"panva","product":"jose-node-esm-runtime"}],"references":[{"url":"https://github.com/panva/jose/security/advisories/GHSA-4v4g-726h-xvfv","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://www.npmjs.com/package/jose-node-esm-runtime","tags":["x_refsource_MISC","x_transferred","Product","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29445","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4v4g-726h-xvfv"},{"url":"https://github.com/panva/jose","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-29445","title":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime","description":"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 `\u003e=3.11.4`. Users should upgrade to `^3.11.4`.","status":"published","published":"2021-04-16T21:50:13Z","modified":"2024-08-03T22:02:51.975Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:33:06.32268Z"}],"euvd":[{"id":"EUVD-2021-0760","description":"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 `\u003e=3.11.4`. Users should upgrade to `^3.11.4`.","status":"published","published":"2021-04-16T21:50:13Z","modified":"2024-08-03T22:02:51Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T03:24:45.541615Z"}],"ghsa":[{"id":"GHSA-4v4g-726h-xvfv","title":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime","description":"### 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.","status":"published","published":"2021-04-19T14:59:06Z","modified":"2023-03-17T17:49:49Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-203","CWE-208","CWE-696"],"updated_at":"2026-11-02T14:36:48.041653Z"}],"nvd":[{"id":"CVE-2021-29445","description":"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 `\u003e=3.11.4`. Users should upgrade to `^3.11.4`.","status":"published","published":"2021-04-16T22:15:14.06Z","modified":"2026-06-17T03:47:39.353Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:06:52.03307Z"}],"osv":[{"id":"CVE-2021-29445","description":"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 `\u003e=3.11.4`. Users should upgrade to `^3.11.4`.","status":"published","published":"2021-04-16T22:15:14.06Z","modified":"2026-10-20T10:53:44.36402754Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:19.129331Z"},{"id":"GHSA-4v4g-726h-xvfv","title":"Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime","description":"### 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.","status":"published","published":"2021-04-19T14:59:06Z","modified":"2026-07-08T06:29:02.11763508Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-203","CWE-208","CWE-696"],"updated_at":"2026-11-02T15:46:37.528068Z"}]}}