The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) and DPC3941T (firmware version DPC3941_2.5s3_PROD_sey) devices allows remote attackers to access the web UI by establishing a session to the wan0 WAN IPv6 address and then entering unspecified hardcoded credentials. This wan0 interface cannot be accessed from the public Internet.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.8, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 4 products from cisco, from cisco, from cisco and 1 other, 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.
2017-07-31T03:29:00.613
2025-04-20T01:37:25.860
Deferred
CVSSv3.0: 8.8 (HIGH)
AV:A/AC:L/Au:N/C:P/I:P/A:P
6.5
6.4
| 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 | dpc3941t_firmware | dpc3941_2.5s3_prod_sey | Yes |
| Hardware | cisco | dpc3941t | - | 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.