HOMEVULNERABILITIESCVE-2017-9521
CRITICAL

CVE-2017-9521

NVD-CWE-noinfoPublished: July 31, 2017· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421733-160420a-CMCST); Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST); Cisco DPC3939B (firmware version dpc3939b-v303r204217-150321a-CMCST); Cisco DPC3941T (firmware version DPC3941_2.5s3_PROD_sey); and Arris TG1682G (eMTA&DOCSIS version 10.0.132.SIP.PC20.CT, software version TG1682_2.2p7s2_PROD_sey) devices allows remote attackers to execute arbitrary code via a specific (but unstated) exposed service. NOTE: the scope of this CVE does NOT include the concept of "Unnecessary Services" in general; the scope is only a single service that is unnecessarily exposed, leading to remote code execution. The details of that service might be disclosed at a later date.

NVD Source

Technical Analysis

CVE-2017-9521 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Cisco6 product(s)
dpc3939 firmwaredpc3939dpc3939b firmwaredpc3939bdpc3941t firmwaredpc3941t
commscope2 product(s)
arris tg1682g firmwarearris tg1682g
Source: NVD CPE · 10 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-32.unnecessary-services.txt
ADVISORYhttps://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-32.unnecessary-services.txt

All References (2)

→
https://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-32.unnecessary-services.txtExploit · Mitigation · Third Party Advisory
→
https://github.com/BastilleResearch/CableTap/blob/master/doc/advisories/bastille-32.unnecessary-services.txtExploit · Mitigation · Third Party Advisory

Quick Facts

CVE IDCVE-2017-9521
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected2 vendor(s)
PublishedJul 31, 2017

Related CVEs (NVD-CWE-noinfo)

CVE-2015-6787
10.0
CVE-2008-5010
10.0
CVE-2010-0071
10.0
CVE-2014-2624
10.0
CVE-2015-5895
10.0
CVE-2006-3698
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2017-9521 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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