The attack targets IKE’s handshake implementation used for IPsec-based VPN connections, opening the door for MiTM attacks or for bad actors to access data carried in VPN sessions.

A researcher challenges a conclusion in a recent academic paper on weak Diffie-Hellman implementations that claims 66 percent of IPsec VPN connections are at risk.

Dear maintainers, We try to connect in Ubuntu 22.04 to an IPsec L2TP VPN with a PSK which uses (how strange?? 😃 ) deprecated and removed DH2 algorithms! In Windows 10, the VPN connection works and ...

Phase 1 apparently completes successfully but after 1 second ISAMP-SA expires and is deleted. VPN log: Mar 13 15:05:40 racoon: [VPN]: INFO: ISAKMP-SA established Site A WAN [500]-Site B WAN[500 ...

A note on IPsec ports: If you’re looking to set up your firewall to allow an IPsec VPN connection, be sure to open UDP port 500 and IP ports 50 and 51.