No exploitation reported

CVE-2017-9521

No exploitation reported by the sources we read.

Published2017-07-31

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC

2017-07-3103:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2017-9521?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2017-9521?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Cisco dpc3939 firmwareversion to verify

Branch	Affected	Fixed in	Source
—	= dpc3939-p20-18-v303r20421733-160420a-cmcst	no fix published	NVD
—	= dpc3939-p20-18-v303r20421746-170221a-cmcst	no fix published	NVD

Commscope arris tg1682g firmwareversion to verify

Branch	Affected	Fixed in	Source
10.0	= 10.0.132.sip.pc20.ct	no fix published	NVD
—	= tg1682_2.2p7s2_prod_sey	no fix published	NVD

Cisco dpc3939b firmwareversion to verify

Branch	Affected	Fixed in	Source
—	= dpc3939b-v303r204217-150321a-cmcst	no fix published	NVD

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

github.comMitigation

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
FIRST EPSSEPSS score3.3 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2017-07-31
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2017-9521?

Is CVE-2017-9521 actively exploited?

Active exploitation of CVE-2017-9521 has not been confirmed. Its EPSS score was 3.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2017-9521?

CVE-2017-9521 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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