Software Engineering Institute

Some versions of the Cisco IOS have a hardcoded SNMP read-write community string. This community string is designed to ensure that DOCSIS-compliant cable modems adhere to RFC 2669.

A vulnerability exists in the enabling of these strings in Cisco IOS versions which do not run on cable modems. An attacker may be able to take control of an affected device by using standard SNMP commands.

Cisco states that the following devices are affected by this vulnerability:

• Cisco IAD2430 Integrated Access Device
• Cisco IAD2431 Integrated Access Device
• Cisco IAD2432 Integrated Access Device
• Cisco VG224 Analog Phone Gateway
• Cisco MWR 1900 Mobile Wireless Edge Router
• Cisco MWR 1941 Mobile Wireless Edge Router

A remote attacker may be able to take control of an affected device.

UpdateCisco has released updates that address this issue. Please see Cisco Security Advisory cisco-sa-20060920-docsis for more details.

In addition to the updates indicated above, Cisco has published a number of workarounds for this issue. Users, particularly those who are not able to apply the updates, are encouraged to implement these workarounds.