CVE-2021-30246

CRITICAL9.1EPSS 0.20%

RSA signature validation vulnerability on maleable encoded message in jsrsasign

Published: 4/16/2021Modified: 11/8/2023

Description

### Impact Vulnerable jsrsasign will accept RSA signature with improper PKCS#1.5 padding. Decoded RSA signature value consists following form: `01(ff...(8 or more ffs)...ff)00[ASN.1 OF DigestInfo]` Its byte length must be the same as RSA key length, however such checking was not sufficient. To make crafted message for practical attack is very hard. ### Patches Users validating RSA signature should upgrade to 10.2.0 or later. ### Workarounds There is no workaround. Not to use RSA signature validation in jsrsasign. ### ACKNOWLEDGEMENT Thanks to Daniel Yahyazadeh @yahyazadeh for reporting and analyzing this vulnerability.

Affected packages (1)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1CRITICAL9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References (5)