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IKE

IKE negotiates IPsec VPN tunnels. Attackers enumerate transform sets, fingerprint vendors, exploit aggressive mode to capture PSKs, and crack weak credentials to gain VPN access

:4500 8 guides 3 phases
1 min read Updated: Jul 14, 2026

What is IKE (NAT-T)?
IKE is the IPsec VPN handshake protocol that authenticates peers and negotiates encryption keys; NAT-T means it runs over UDP (typically 4500) so VPN traffic works through NAT.

Common security issues

  • Weak or reused PSKs enabling brute-force/offline cracking (especially legacy IKEv1)

  • Aggressive exposure of the VPN gateway increasing DoS risk via handshake floods

  • Weak crypto settings (old ciphers/DH groups) reducing tunnel security

  • Configuration leaks and fingerprinting that help attackers target specific VPN stacks

Enumeration

IKE detection, transform set probing, and vendor ID fingerprinting guides

3

Vulnerability Discovery

IKE vuln guides: aggressive mode, weak ciphers, IKEv1 detection

3

Exploitation

PSK capture, cracking, and weak transform VPN access guides

2