The virtual private dial-up network (VPDN) component in Cisco IOS before 12.3 allows remote attackers to cause a denial of service (resource exhaustion) via a series of PPTP sessions, related to the persistence of interface descriptor block (IDB) data structures after process termination, aka bug ID CSCdv59309.
La componente red privada virtual dial-up (VPDN) de Cisco IOS versiones anteriores a 12.3 permite a atacantes remotos provocar una denegación de servicio (agotamiento de recursos) a través de una serie de sesiones PPTP, en relación con la persistencia de las estructuras de datos de la interfaz de descriptor de bloque (BID) después de la terminación proceso, también conocido como bug CSCdv59309 ID.
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. The first vulnerability is a memory leak that occurs as a result of PPTP session termination. The second vulnerability may consume all interface descriptor blocks on the affected device because those devices will not reuse virtual access interfaces. If these vulnerabilities are repeatedly exploited, the memory and/or interface resources of the attacked device may be depleted.
