CVE-2017-9521

Exp

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.

Published: 2017-07-30 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-9521 is rated High Exploit Risk (85.6/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.26%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.09% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2017-9521

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2017-9521

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.17% 3.26% +1.09%
2 2026-04-03 2.32% 2.17% -0.15%
3 2025-03-30 — 2.32% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-9521

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2017-9521

Affected software / configurations for CVE-2017-9521

Vendor Product Version Raw CPE
cisco dpc3939_firmware dpc3939-p20-18-v303r20421733-160420a-cmcst cpe:2.3:o:cisco:dpc3939_firmware:dpc3939-p20-18-v303r20421733-160420a-cmcst:*:*:*:*:*:*:*
cisco dpc3939_firmware dpc3939-p20-18-v303r20421746-170221a-cmcst cpe:2.3:o:cisco:dpc3939_firmware:dpc3939-p20-18-v303r20421746-170221a-cmcst:*:*:*:*:*:*:*
cisco dpc3939b_firmware dpc3939b-v303r204217-150321a-cmcst cpe:2.3:o:cisco:dpc3939b_firmware:dpc3939b-v303r204217-150321a-cmcst:*:*:*:*:*:*:*
cisco dpc3941t_firmware dpc3941_2.5s3_prod_sey cpe:2.3:o:cisco:dpc3941t_firmware:dpc3941_2.5s3_prod_sey:*:*:*:*:*:*:*
commscope arris_tg1682g_firmware 10.0.132.sip.pc20.ct cpe:2.3:o:commscope:arris_tg1682g_firmware:10.0.132.sip.pc20.ct:*:*:*:*:*:*:*
commscope arris_tg1682g_firmware tg1682_2.2p7s2_prod_sey cpe:2.3:o:commscope:arris_tg1682g_firmware:tg1682_2.2p7s2_prod_sey:*:*:*:*:*:*:*

References for CVE-2017-9521

cvelogic Threat Intelligence