[原文]Cisco VPN 3000 series concentrators before 2.5.2(F) allow remote attackers to cause a denial of service via a flood of invalid login requests to (1) the SSL service, or (2) the telnet service, which do not properly disconnect the user after several failed login attempts.
Cisco VPN 3000 series concentrators contain a flaw that may allow a remote denial of service. The issue is triggered when the SSL or regular telnet session does not disconnect after repeated failed attempts and the system keeps trying to interpret the incoming data causing a shortage of memory on the system resulting in a reboot, and will result in loss of availability for the service.
Upgrade to version 2.5.2(F) or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.