During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2-1.0.2o).
https://www.tenable.com/security/tns-2018-17
https://www.tenable.com/security/tns-2018-14
https://www.tenable.com/security/tns-2018-13
https://www.tenable.com/security/tns-2018-12
https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
https://www.oracle.com/security-alerts/cpujan2021.html
https://www.oracle.com/security-alerts/cpuapr2020.html
https://www.openssl.org/news/secadv/20180612.txt
https://www.debian.org/security/2018/dsa-4355
https://www.debian.org/security/2018/dsa-4348
https://usn.ubuntu.com/3692-2/
https://usn.ubuntu.com/3692-1/
https://securityadvisories.paloaltonetworks.com/Home/Detail/133
https://security.netapp.com/advisory/ntap-20190118-0002/
https://security.netapp.com/advisory/ntap-20181105-0001/
https://security.gentoo.org/glsa/201811-03
https://nodejs.org/en/blog/vulnerability/august-2018-security-releases/
https://lists.debian.org/debian-lts-announce/2018/07/msg00043.html
https://cert-portal.siemens.com/productcert/pdf/ssa-419820.pdf
https://access.redhat.com/errata/RHSA-2019:1543
https://access.redhat.com/errata/RHSA-2019:1297
https://access.redhat.com/errata/RHSA-2019:1296
https://access.redhat.com/errata/RHSA-2018:3505
https://access.redhat.com/errata/RHSA-2018:3221
https://access.redhat.com/errata/RHSA-2018:2553
https://access.redhat.com/errata/RHSA-2018:2552
http://www.securitytracker.com/id/1041090
http://www.securityfocus.com/bid/104442
http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html