CVE-2021-40404Network attack vector

Unauthenticated access via JSON command bypass

Published Jan 28, 2022 · Updated Apr 15, 2025

Authentication bypass in Reolink RLC-410W v3.0.0.136_20121102 allows remote attackers to access protected camera APIs via HTTP. The cgiserver.cgi parser authorizes requests by checking the URL cmd parameter while executing commands supplied in a JSON body array, allowing a non-Login command to evade the login gate. No credentials or user interaction are required; reachable devices can expose APIs intended for authenticated sessions, with integrity impact demonstrated by Talos.

CVSS severity5.3
Medium
EPSS probability1.23%
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 Reolink RLC-410W v3.0.0.136_20121102 allows remote attackers to access protected camera APIs via HTTP. The cgiserver.cgi parser authorizes requests by checking the URL cmd parameter while executing commands supplied in a JSON body array, allowing a non-Login command to evade the login gate. No credentials or user interaction are required; reachable devices can expose APIs intended for authenticated sessions, with integrity impact demonstrated by Talos.

The record

CVE
CVE-2021-40404
Published
Jan 28, 2022
Updated
Apr 15, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-284, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 28, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
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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