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.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 2 products from cisco, from cisco organizations running these solutions should prioritize assessment and patching.
First disclosed in 2017, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.
2017-07-31T03:29:00.300
2025-04-20T01:37:25.860
Deferred
CVSSv3.0: 7.5 (HIGH)
AV:N/AC:L/Au:N/C:P/I:N/A:N
10.0
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | cisco | dpc3939_firmware | dpc3939-p20-18-v303r20421746-170221a-cmcst | Yes |
| Hardware | cisco | dpc3939 | - | No |
| Operating System | cisco | dpc3939_firmware | dpc3939-p20-18-v303r20421733-160420a-cmcst | Yes |
| Hardware | cisco | dpc3939 | - | No |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For cisco's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.