CVE-2017-9481: Cisco DPC3939 Firmware

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices allows remote attackers to obtain unintended access to the Network Processor (NP) 169.254/16 IP network by adding a routing-table entry that specifies the LAN IP address as the router for that network.

Affected products

• Cisco DPC3939 Firmware: version dpc3939-p20-18-v303r20421746-170221a-cmcst only

Published 2017-07-31. Last modified 2026-06-17.