CVE-2017-9521

Name: CVE-2017-9521
Creator: NVD / NIST
Published: 2017-07-31T03:29:00.973+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.26%

Last modified Jun 17, 2026

CVE-2017-9521 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 3.26% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

3.26%

86.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Cisco	Dpc3939 Firmware	dpc3939-p20-18-v303r20421733-160420a-cmcst
Cisco	Dpc3939 Firmware	dpc3939-p20-18-v303r20421746-170221a-cmcst
Cisco	Dpc3939b Firmware	dpc3939b-v303r204217-150321a-cmcst
Cisco	Dpc3941t Firmware	dpc3941_2.5s3_prod_sey
Commscope	Arris Tg1682g Firmware	10.0.132.sip.pc20.ct
Commscope	Arris Tg1682g Firmware	tg1682_2.2p7s2_prod_sey

References

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

Timeline

Published: Jul 31, 2017
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-9521?

How severe is CVE-2017-9521?

CVE-2017-9521 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.26% probability of exploitation in the next 30 days.

How do I fix CVE-2017-9521?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2017-9521?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST