TI-2017-06886 Aliases CVE-2017-9478 GHSA-wcmp-jh6v-8592

The Comcast firmware on Cisco DPC3939 (firmware version…

LOW 36CWE-200Published 2017-07-31 · Updated 2024-08-05

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: High · None · None
Fix status: No fix listed

Attack profile from CVSS 3.0 · NVD. Fix status from CNA. Impact type from CWE-200.

Summary

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.

Why it matters now

EPSS 0.0151 74th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 3

CPE	Versions	Role	Vendor
cpe:2.3:o:cisco:dpc3939_firmware:dpc3939-p20-18-v303r20421746-170221a-cmcst:::::::*	dpc3939-p20-18-v303r20421746-170221a-cmcst	Vulnerable	Cisco
cpe:2.3:h:cisco:dpc3939:-:::::::*	not specified by NVD	Running on	Cisco
cpe:2.3:o:cisco:dpc3939_firmware:dpc3939-p20-18-v303r20421733-160420a-cmcst:::::::*	dpc3939-p20-18-v303r20421733-160420a-cmcst	Vulnerable	Cisco

cpe:2.3:o:cisco:dpc3939_firmware:dpc3939-p20-18-v303r20421746-170221a-cmcst:*:*:*:*:*:*:* Versions dpc3939-p20-18-v303r20421746-170221a-cmcst Vulnerable ·Cisco
cpe:2.3:h:cisco:dpc3939:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
cpe:2.3:o:cisco:dpc3939_firmware:dpc3939-p20-18-v303r20421733-160420a-cmcst:*:*:*:*:*:*:* Versions dpc3939-p20-18-v303r20421733-160420a-cmcst Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2017-9478
2026-10-03 Alias added: GHSA-wcmp-jh6v-8592

References

Exploit 1

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

TI-2017-06927 The Comcast firmware on Cisco DPC3939 (firmware version… CVSS 3.1CRITICAL 9.8
TI-2017-06887 The Comcast firmware on Cisco DPC3939 (firmware version… CVSS 3.0CRITICAL 9.8
TI-2017-06890 The Comcast firmware on Cisco DPC3939 (firmware version… CVSS 3.0CRITICAL 9.8
TI-2017-06891 The Comcast firmware on Cisco DPC3939 (firmware version… CVSS 3.0CRITICAL 9.8
TI-2017-06896 The Comcast firmware on Cisco DPC3939 (firmware version… CVSS 3.0HIGH 8.8
TI-2017-06900 The Comcast firmware on Cisco DPC3939 (firmware version… CVSS 3.1HIGH 7.5

See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences