{"id":"CVE-2021-30246","aliases":["EUVD-2021-0736","GHSA-27fj-mc8w-j9wg"],"status":"published","title":"RSA signature validation vulnerability on maleable encoded message in jsrsasign","description":"In the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized to be valid. NOTE: there is no known practical attack.","severity":{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.0096,"percentile":0.61968,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-347"],"published":"2021-04-07T20:11:56Z","modified":"2026-10-20T10:54:39Z","fixes":[{"ecosystem":"npm","package":"jsrsasign","fixed_in":["10.2.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"jsrsasign","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.2.0"}]}]},{"source":"osv","ecosystem":"npm","package":"jsrsasign","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"10.2.0"}]}]}],"products":[{"vendor":"kjur","product":"jsrsasign"}],"references":[{"url":"https://kjur.github.io/jsrsasign/","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory"]},{"url":"https://github.com/kjur/jsrsasign/issues/478","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/kjur/jsrsasign/releases/tag/10.1.13","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory","web"]},{"url":"https://github.com/kjur/jsrsasign/security/advisories/GHSA-27fj-mc8w-j9wg","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-30246","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-27fj-mc8w-j9wg"},{"url":"https://kjur.github.io/jsrsasign","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-30246","description":"In the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized to be valid. NOTE: there is no known practical attack.","status":"published","published":"2021-04-07T20:11:56Z","modified":"2024-08-03T22:24:59.577Z","updated_at":"2026-11-02T14:33:02.20241Z"}],"euvd":[{"id":"EUVD-2021-0736","description":"In the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized to be valid. NOTE: there is no known practical attack.","status":"published","published":"2021-04-07T20:11:56Z","modified":"2024-08-03T22:24:59Z","updated_at":"2026-11-03T03:24:43.413555Z"}],"ghsa":[{"id":"GHSA-27fj-mc8w-j9wg","title":"RSA signature validation vulnerability on maleable encoded message in jsrsasign","description":"### Impact\nVulnerable jsrsasign will accept RSA signature with improper PKCS#1.5 padding.\nDecoded RSA signature value consists following form:\n`01(ff...(8 or more ffs)...ff)00[ASN.1 OF DigestInfo]`\nIts byte length must be the same as RSA key length, however such checking was not sufficient.\n\nTo make crafted message for practical attack is very hard.\n\n### Patches\nUsers validating RSA signature should upgrade to 10.2.0 or later.\n\n### Workarounds\nThere is no workaround. Not to use RSA signature validation in jsrsasign.\n\n### ACKNOWLEDGEMENT\nThanks to Daniel Yahyazadeh @yahyazadeh for reporting and analyzing this vulnerability.","status":"published","published":"2021-04-16T19:52:35Z","modified":"2023-09-11T18:42:08Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:37:03.916765Z"}],"nvd":[{"id":"CVE-2021-30246","description":"In the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized to be valid. NOTE: there is no known practical attack.","status":"published","published":"2021-04-07T21:15:16.153Z","modified":"2026-06-22T03:18:31.867Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"primary"},{"version":"2.0","score":6.4,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:06:51.610648Z"}],"osv":[{"id":"CVE-2021-30246","description":"In the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized to be valid. NOTE: there is no known practical attack.","status":"published","published":"2021-04-07T21:15:16.153Z","modified":"2026-10-20T10:54:39.421453563Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"updated_at":"2026-11-02T15:44:19.483607Z"},{"id":"GHSA-27fj-mc8w-j9wg","title":"RSA signature validation vulnerability on maleable encoded message in jsrsasign","description":"### Impact\nVulnerable jsrsasign will accept RSA signature with improper PKCS#1.5 padding.\nDecoded RSA signature value consists following form:\n`01(ff...(8 or more ffs)...ff)00[ASN.1 OF DigestInfo]`\nIts byte length must be the same as RSA key length, however such checking was not sufficient.\n\nTo make crafted message for practical attack is very hard.\n\n### Patches\nUsers validating RSA signature should upgrade to 10.2.0 or later.\n\n### Workarounds\nThere is no workaround. Not to use RSA signature validation in jsrsasign.\n\n### ACKNOWLEDGEMENT\nThanks to Daniel Yahyazadeh @yahyazadeh for reporting and analyzing this vulnerability.","status":"published","published":"2021-04-16T19:52:35Z","modified":"2023-11-08T04:05:45.910717Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:46:33.956911Z"}]}}