The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices allows remote attackers to execute arbitrary commands as root by leveraging local network access and connecting to the syseventd server, as demonstrated by copying configuration data into a readable filesystem.

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices allows remote attackers to obtain root access to the Network Processor (NP) Linux system by enabling a TELNET daemon (through CVE-2017-9479 exploitation) and then establishing a TELNET session.

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices allows local users (e.g., users who have command access as a consequence of CVE-2017-9479 exploitation) to read arbitrary files via UPnP access to /var/IGD/.