Networking

TCP Initial Sequence Number (ISN)

The starting sequence number a host chooses for a new TCP connection. If ISNs are predictable, an attacker who cannot see the traffic can still forge packets that the receiver accepts as part of an existing connection, enabling spoofing and connection hijacking.

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How DTLS Works and Why It Widens a VPN Gateway's Attack Surface

DTLS carries TLS over UDP for faster VPN tunnels, and it is usually on by default. What the protocol adds, why that code is pre-authentication attack surface, and how to decide whether to disable it.

intermediate 6 min read

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