CVE-2012-5977

Asterisk Open Source v1.8.x anteriores a v1.8.19.1, v10.x anteriores a v10.11.1, y v11.x anteriores a v11.1.2; Certified Asterisk v1.8.11 anteriores a v1.8.11-cert10; y Asterisk Digiumphones v10.x-digiumphones anteriores a v10.11.1-digiumphones, cuando están permitidas las llamadas anónimas, permiten a atacantes remotos a provocar una denegación de servicio(consumo de recursos) haciendo llamadas anónimas desde múltiples fuentes y en consecuencia, añadir varias entradas a la caché de estado del dispositivo.

Asterisk maintains an internal cache for devices. The device state cache holds the state of each device known to Asterisk, such that consumers of device state information can query for the last known state for a particular device, even if it is not part of an active call. The concept of a device in Asterisk can include things that do not have a physical representation. One way that this currently occurs is when anonymous calls are allowed in Asterisk. A device is automatically created and stored in the cache for each anonymous call that occurs; this is possible in the SIP and IAX2 channel drivers and through channel drivers that utilize the res_jabber/res_xmpp resource modules (Gtalk, Jingle, and Motif). Attackers exploiting this vulnerability can attack an Asterisk system configured to allow anonymous calls by varying the source of the anonymous call, continually adding devices to the device state cache and consuming a system's resources.