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tls certificate validation
About this tag
TLS certificate validation is a critical security mechanism that ensures a client connects to the intended server by verifying the server's certificate against trusted authorities. On WindowsForum.com, discussions highlight vulnerabilities where improper TLS certificate validation can lead to serious trust risks, particularly in industrial software. For example, CVE-2025-11043 in ABB Automation Studio versions before 6.5 fails to properly validate server certificates in OPC UA and ANSL-over-TLS connections, allowing network-based attackers to impersonate trusted servers. Such flaws underscore the importance of rigorous certificate validation in encrypted communications, especially in operational technology environments where trust is foundational. The tag covers topics related to certificate validation bugs, security advisories, and best practices for maintaining secure TLS connections.
CISA republished ABB’s advisory for CVE-2025-11043 on May 5, 2026, warning that B&R Automation Studio versions before 6.5 improperly validate server certificates in OPC UA and ANSL-over-TLS client connections, enabling a network-positioned attacker to impersonate a trusted server. The bug is not...