PT-2017-18951 · Cisco · Cisco Dpc3939

Chris Grayson + 2 · Published 2017-07-31 · Updated 2017-08-03 · CVE-2017-9478

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions Cisco DPC3939 version dpc3939-P20-18-v303r20421733-160420a-CMCST Cisco DPC3939 version dpc3939-P20-18-v303r20421746-170221a-CMCST

Description The issue allows remote attackers to discover hidden Home Security Wi-Fi networks. This is possible because the Comcast firmware on the devices sets the CM MAC address to a value with a two-byte offset from the MTA/VoIP MAC address, which is embedded into the DNS hostname.

Recommendations For Cisco DPC3939 version dpc3939-P20-18-v303r20421733-160420a-CMCST, update the firmware to a version that does not embed the MTA/VoIP MAC address into the DNS hostname. For Cisco DPC3939 version dpc3939-P20-18-v303r20421746-170221a-CMCST, update the firmware to a version that does not embed the MTA/VoIP MAC address into the DNS hostname. As a temporary workaround, consider restricting access to the DNS hostname to minimize the risk of exploitation.

Exploit

Fix

Information Disclosure

Weakness Enumeration

CWE-200

Related Identifiers

CVE-2017-9478

Affected Products

Cisco Dpc3939

References · 3

• 🔥 https://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-20.emta-reverse-dns.txt · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2017-9478 · Security Note
• https://osv.dev/vulnerability/CVE-2017-9478 · Vendor Advisory