Cisco IOS Virtual Private Dial-up Network Denial of Service Vulnerability

Two vulnerabilities exist in the virtual private dial-up network (VPDN) solution when Point-to-Point Tunneling Protocol (PPTP) is used in certain Cisco IOS releases prior to 12.3. PPTP is only one of the supported tunneling protocols used to tunnel PPP frames within the VPDN solution.

URL: http://www.cisco.com/en/US/products/products_security_advisory09186a0080969862.shtml