Vulnerability Instance

Security Update for the OPC UA .NET Standard Stack
This security update resolves a vulnerability in the OPC UA .NET Standard Stack that allows an unauthorized attacker to bypass application authentication when the deprecated Basic128Rsa15 security policy is enabled.

Note that the Basic128Rsa15 is disabled by default so most users will not be affected. When this patch is applied the Server closes all channels using the Basic128Rsa15 if an attack is detected. This introduces a DoS before any compromise can occur which is preferable to a compromise. To prevent this failure, applications must stop using Basic128Rsa15.