CVE-2017-9478

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2017-07-31 · updated 2026-06-17
Weakness: CWE-200

Description

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421733-160420a-CMCST) and DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices sets the CM MAC address to a value with a two-byte offset from the MTA/VoIP MAC address, which indirectly allows remote attackers to discover hidden Home Security Wi-Fi networks by leveraging the embedding of the MTA/VoIP MAC address into the DNS hostname.

Affected products

Cisco Dpc3939 Firmware: dpc3939-p20-18-v303r20421746-170221a-cmcst, dpc3939-p20-18-v303r20421733-160420a-cmcst

References

https://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-20.emta-reverse-dns.txt
https://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-20.emta-reverse-dns.txt

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