CVE-2021-45657

Local impact via server-side injection

Published Dec 26, 2021 · Updated Aug 4, 2024

Improper input neutralization in NETGEAR router firmware allows local users to affect confidentiality and integrity via server-side injection. The vendor identifies the vulnerable operation only as server-side injection and does not publish the affected component or exact parsing flaw. Reachability requires low-privilege local access to the device; the CNA assessment reports no availability impact.

CVSS severity7.1
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input neutralization in NETGEAR router firmware allows local users to affect confidentiality and integrity via server-side injection. The vendor identifies the vulnerable operation only as server-side injection and does not publish the affected component or exact parsing flaw. Reachability requires low-privilege local access to the device; the CNA assessment reports no availability impact.

The record

CVE
CVE-2021-45657
Published
Dec 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-74
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.1NETGEARCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

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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