CVE-2018-21212

Unauthenticated buffer overflow via pre-authentication request

Published Apr 28, 2020 · Updated Aug 5, 2024

Buffer overflow in NETGEAR routers and extenders before listed fixed versions allows remote attackers to cause unspecified impact via network requests. The pre-authentication request parser copies attacker-controlled data into a fixed-size buffer without adequate bounds checks; the vendor does not identify the exact function or parameter. Unauthenticated attackers on an adjacent network can reach the service without login, while consequences beyond the overflow are not disclosed.

CVSS severity8.8
High
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in NETGEAR routers and extenders before listed fixed versions allows remote attackers to cause unspecified impact via network requests. The pre-authentication request parser copies attacker-controlled data into a fixed-size buffer without adequate bounds checks; the vendor does not identify the exact function or parameter. Unauthenticated attackers on an adjacent network can reach the service without login, while consequences beyond the overflow are not disclosed.

The record

CVE
CVE-2018-21212
Published
Apr 28, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 28, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.8NVDAV:A/AC:L/Au:N/C:P/I:P/A:P
8.8NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.8MITRE CNACVSS:3.0/AV:A/AC:L/PR:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

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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