Behavioral discrepancy information leak in Juniper Netscreen VPN running ScreenOS 5.2.0 and earlier, when using IKE with pre-shared key authentication, allows remote attackers to enumerate valid usernames via an IKE Aggressive Mode packet, which generates a response if the username is valid but does not respond when the username is invalid.

Behavioral discrepancy information leak in Juniper Netscreen VPN running ScreenOS 5.2.0 and earlier, when using IKE with pre-shared key authentication, allows remote attackers to enumerate valid usernames via an IKE Aggressive Mode packet, which generates a response if the username is valid but does not respond when the username is invalid.