An issue was discovered in OPC UA .NET Standard Stack and Sample Code before GitHub commit 2018-04-12, and OPC UA .NET Legacy Stack and Sample Code before GitHub commit 2018-03-13. A vulnerability in OPC UA applications can allow a remote attacker to determine a Server’s private key by sending carefully constructed bad UserIdentityTokens as part of an oracle attack.
www.securityfocus.com/bid/108688
github.com/OPCFoundation/UA-.NET-Legacy/commit/e2a781b38efb8686d2bd850c2f2372b5c670bc45
github.com/OPCFoundation/UA-.NETStandard/commit/ebcf026a54dd0c9052cff009d96d827ac923d150
opcfoundation-onlineapplications.org/faq/SecurityBulletins/OPC_Foundation_Security_Bulletin_CVE-2018-7559.pdf