GHSA-27fj-mc8w-j9wg
RSA signature validation vulnerability on maleable encoded message in jsrsasign
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### 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.
References
External links from the advisory. They lead to third-party sites.