CVE-2021-20305

A flaw was found in Nettle in versions before 3.7.2, where several Nettle
signature verification functions (GOST DSA, EDDSA & ECDSA) result in the
Elliptic Curve Cryptography point (ECC) multiply function being called with
out-of-range scalers, possibly resulting in incorrect results. This flaw
allows an attacker to force an invalid signature, causing an assertion
failure or possible validation. The highest threat to this vulnerability is
to confidentiality, integrity, as well as system availability.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=985652&gt;