CVE-2018-21157

Authenticated command execution via undisclosed command injection

Published Apr 27, 2020 · Updated Aug 5, 2024

OS command injection in NETGEAR router firmware allows remote authenticated users on the local network to execute arbitrary commands. Neither the vendor advisory nor the CVE record identifies the affected request handler, parameter, or shell-command construction. Administrative access and adjacent-network reachability are required, and successful command execution can compromise the router.

CVSS severity6.8
Medium
EPSS probability0.85%
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 router firmware allows remote authenticated users on the local network to execute arbitrary commands. Neither the vendor advisory nor the CVE record identifies the affected request handler, parameter, or shell-command construction. Administrative access and adjacent-network reachability are required, and successful command execution can compromise the router.

The record

CVE
CVE-2018-21157
Published
Apr 27, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-78, T1059
Attack vector
adjacent
Privileges
admin

Timeline

How it unfolded

  1. Apr 27, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NETGEARCVSS:3.0/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
5.2NIST NVDAV:A/AC:L/Au:S/C:P/I:P/A:P
6.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

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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