Description
In the Bouncy Castle JCE Provider version 1.55 and earlier the other party DH public key is not fully validated. This can cause issues as invalid keys can be used to reveal details about the other party's private key where static Diffie-Hellman is in use. As of release 1.56 the key parameters are checked on agreement calculation.
Remediation
References
https://access.redhat.com/errata/RHSA-2018:2669
https://access.redhat.com/errata/RHSA-2018:2927
https://github.com/bcgit/bc-java/commit/1127131c89021612c6eefa26dbe5714c194e7495#diff-d525a20b8acaed791ae2f0f770eb5937
https://lists.debian.org/debian-lts-announce/2018/07/msg00009.html
https://security.netapp.com/advisory/ntap-20181127-0004/
https://usn.ubuntu.com/3727-1/
https://www.oracle.com/security-alerts/cpuoct2020.html