CVE-2018-21147

Authenticated memory corruption via stack overflow

Published Apr 21, 2020 · Updated Aug 5, 2024

A stack-based buffer overflow in NETGEAR router firmware allows remote authenticated users to trigger memory corruption over an adjacent network. NETGEAR has not published the affected component, attacker-controlled input, or the operation that exceeds the stack buffer. Administrative privileges and adjacent-network access are required; public sources do not distinguish a crash from data disclosure or code execution.

CVSS severity6.8
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A stack-based buffer overflow in NETGEAR router firmware allows remote authenticated users to trigger memory corruption over an adjacent network. NETGEAR has not published the affected component, attacker-controlled input, or the operation that exceeds the stack buffer. Administrative privileges and adjacent-network access are required; public sources do not distinguish a crash from data disclosure or code execution.

The record

CVE
CVE-2018-21147
Published
Apr 21, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
adjacent
Privileges
admin

Timeline

How it unfolded

  1. Apr 21, 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

6.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
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

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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