The OPC autogenerated ANSI C stack stubs (in the NodeSets) do not handle all error cases. This can lead to a NULL pointer dereference.

In OPC Foundation Local Discovery Server (LDS) before 1.04.402.463, remote attackers can cause a denial of service (DoS) by sending carefully crafted messages that lead to Access of a Memory Location After the End of a Buffer.

OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.

A Privilege Elevation vulnerability in OPC UA .NET Standard Stack 1.4.363.107 could allow a rogue application to establish a secure connection.

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.

In OPC Foundation OPC UA .NET Standard codebase 1.4.357.28, servers do not create sufficiently random numbers in OPCFoundation.NetStandard.Opc.Ua before 1.4.359.31, which allows man in the middle attackers to reuse encrypted user credentials sent over the network.

Failure to validate certificates in OPC Foundation UA Client Applications communicating without security allows attackers with control over a piece of network infrastructure to decrypt passwords.

An XXE vulnerability in the OPC UA Java and .NET Legacy Stack can allow remote attackers to trigger a denial of service.

Buffer overflow in OPC UA applications allows remote attackers to trigger a stack overflow with carefully structured requests.

Unsigned versions of the DLLs distributed by the OPC Foundation may be replaced with malicious code.