Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:10 relevant versions.
It was found that Diffie Hellman Client key exchange handling in NSS 3.21.x was vulnerable to small subgroup confinement attack. An attacker could use this flaw to recover private keys by confining the client DH key to small subgroup of the desired group.
nss to version 2:3.25-1 or higher.