|  |  | A Management Information Base (MIB) is what SNMP uses to gather or change information on a device. Cisco supports an old MIB called OLD_CISCO_SYS_MIB, which allows people to view and change the configuration file on a Cisco router. Even if the hacker does not change the configuration of your router through this exploit, he can view your security access list to find a way around them or attempt to crack your passwords. There are freeware hacker tools designed for the sole purpose of cracking Cisco passwords. To see if your device is vulnerable, contact Cisco at: ftp://ftp.cisco.com/pub/mibs/supportlists