CVE-2021-20173Public exploit

Authenticated command execution via unsanitized update values

Published Dec 30, 2021 · Updated Aug 3, 2024

OS command injection in NETGEAR Nighthawk R6700v3 1.0.4.120 allows remote authenticated users to execute commands through SOAP. The default upnpd service inserts firmware-update configuration values into wget command strings and passes them unsanitized to system(). A valid router session and a modified configuration value are required, after which commands execute with the service's device privileges.

CVSS severity8.8
High
EPSS probability3.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in NETGEAR Nighthawk R6700v3 1.0.4.120 allows remote authenticated users to execute commands through SOAP. The default upnpd service inserts firmware-update configuration values into wget command strings and passes them unsanitized to system(). A valid router session and a modified configuration value are required, after which commands execute with the service's device privileges.

The record

CVE
CVE-2021-20173
Published
Dec 30, 2021
Updated
Aug 3, 2024
Vendor
NETGEAR
Product
Nighthawk AC1750 Smart WiFi Router (R6700v3)
Classifications
CWE-78, T1059.004
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.4.120

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

NETGEAR · Nighthawk AC1750 Smart WiFi Router (R6700v3)version=1.0.4.120

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.1TenableCVSS:3.0/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NVDAV:N/AC:L/Au:S/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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