What is CVE-2021-40404?

CVE-2021-40404 is a medium-severity vulnerability in Reolink Rlc-410w, classified under Improper Access Control. CVSS score: 6.5/10. Published 2022-01-28.

How severe is CVE-2021-40404?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2021-40404 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Reolink Rlc-410w

CVE-2021-40404

An authentication bypass vulnerability exists in the cgiserver.cgi Login functionality of reolink RLC-410W v3.0.0.136_20121102. A specially-crafted HTTP request can lead to authentication bypass. An attacker can send an HTTP request to trigger this vulnerability.

Published 2022-01-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (67.9th percentile), scored 2026-10-07.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 67.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Reolink Rlc-410w
Reolink Rlc-410w Firmware — versions 3.0.0.136_20121102

Weakness classification (CWE)

Public proof-of-concept exploits

aredspy/ReoLink-Reboot

References

talosintelligence.com/vulnerability_reports/TALOS-2021-1420 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-40404?: CVE-2021-40404 is a medium-severity vulnerability in Reolink Rlc-410w, classified under Improper Access Control. CVSS score: 6.5/10. Published 2022-01-28.
How severe is CVE-2021-40404?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-40404 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.