CVE-2021-45504

Unauthenticated access to undisclosed protected functions

Published Dec 26, 2021 · Updated Aug 4, 2024

Authentication bypass in NETGEAR CBR40, CBR750, RBR850, RBR852, and RBS850 firmware allows remote attackers to gain unauthorized access. NETGEAR has not published the affected interface, request path, or authentication check that incorrectly accepts unauthenticated input. Affected versions are CBR40 before 2.5.0.24, CBR750 before 4.6.3.6, and RBR850, RBR852, and RBS850 before 3.2.17.12; exploitation requires adjacent-network reachability, and the protected functions exposed remain undisclosed.

CVSS severity9.8
Critical
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in NETGEAR CBR40, CBR750, RBR850, RBR852, and RBS850 firmware allows remote attackers to gain unauthorized access. NETGEAR has not published the affected interface, request path, or authentication check that incorrectly accepts unauthenticated input. Affected versions are CBR40 before 2.5.0.24, CBR750 before 4.6.3.6, and RBR850, RBR852, and RBS850 before 3.2.17.12; exploitation requires adjacent-network reachability, and the protected functions exposed remain undisclosed.

The record

CVE
CVE-2021-45504
Published
Dec 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
Unavailable
Attack vector
adjacent
Privileges
unauthenticated

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

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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

7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.6NETGEARCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/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

No sourced classifications are available.

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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