CVE-2011-0321

librpc.dll en nsrexecd de EMC NetWorker en versiones anteriores a 7.5 SP4, 7.5.3.x anteriores a 7.5.3.5, y 7.6.x anteriores a 7.6.1.2 no mitiga apropiadamente la posibilidad de suplantar una dirección IP de fuente localhost, lo que permite a atacantes remotos (1) registrar o (2) desregistrar servicios RPC, y consecuentemente provocar una denegación de servicio u obtener información confidencial de comunicación entre procesos ("interprocess communication") a través de paquetes UDP modificados que contengan comandos de servicio.

This vulnerability allows remote attackers to register RPC services on vulnerable installations of EMC Legato Networker and IBM Informix Dynamic Server. Authentication is not required to exploit this vulnerability.
The flaw exists within the librpc.dll component which listens by default on UDP port 111. When handling the pmap_set request the process verifies the source address is "127.0.0.1". This communication is via UDP and a valid source address is not required, a udp packet from source address "127.0.0.1" can be created sent to this service allowing a remote attacker to register and unregister RPC services. A remote attack can use this vulnerability to create a denial of service condition or eavesdrop on process communications.