The remote-access IPSec VPN implementation on Cisco Adaptive Security Appliances (ASA) 5500 series devices, PIX Security Appliances 500 series devices, and VPN Concentrators 3000 series devices responds to an Aggressive Mode IKE Phase I message only when the group name is configured on the device, which allows remote attackers to enumerate valid group names via a series of IKE negotiation attempts, aka Bug ID CSCtj96108, a different vulnerability than CVE-2005-2025.