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.
References (1)
Core 1
Core References
Exploit, Third Party Advisory x_refsource_misc
https://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-20.emta-reverse-dns.txt
Scores
CVSS v3
7.5
EPSS
0.0032
EPSS Percentile
54.6%
Attack Vector
NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Details
CWE
CWE-200
Status
published
Products (2)
cisco/dpc3939_firmware
dpc3939-p20-18-v303r20421746-170221a-cmcst
cisco/dpc3939_firmware
dpc3939-p20-18-v303r20421733-160420a-cmcst
Published
Jul 31, 2017
Tracked Since
Feb 18, 2026