How severe is CVE-2021-40407?

CVE-2021-40407 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-40407 being actively exploited?

Yes. CVE-2021-40407 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-12-18, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-40407?

CVE-2021-40407 affects Reolink Rlc-410w Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40407?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-40407 have an EU (EUVD) identifier?

Yes. CVE-2021-40407 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-27584. It is also flagged as exploited in the EUVD (since 2024-12-18).

When was CVE-2021-40407 published?

CVE-2021-40407 was published on 2022-01-28 and last updated on 2026-06-17.

CVE-2021-40407

CVE-2021-40407 is a high-severity vulnerability in Reolink Rlc-410w Firmware with a CVSS 3.x base score of 7.2. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2024-12-18). The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 7.2)
CVSS v2: 7.5
EPSS exploit prediction: 48% (99th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2024-12-18)
EU (EUVD) id: EUVD-2021-27584
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2024-12-18)
Weakness: CWE-78
Affected product: Reolink Rlc-410w Firmware
Published: 2022-01-28
Last modified: 2026-06-17

Description

An OS command injection vulnerability exists in the device network settings functionality of reolink RLC-410W v3.0.0.136_20121102. At [1] or [2], based on DDNS type, the ddns->domain variable, that has the value of the domain parameter provided through the SetDdns API, is not validated properly. This would lead to an OS command injection. An attacker can send an HTTP request to trigger this vulnerability.

Frequently asked questions

What is CVE-2021-40407?: An OS command injection vulnerability exists in the device network settings functionality of reolink RLC-410W v3.0.0.136_20121102. At [1] or [2], based on DDNS type, the ddns->domain variable, that has the value of the domain parameter provided through the SetDdns API, is not validated properly. This would lead to an OS command injection. An attacker can send an HTTP request to trigger this vulnerability.
How severe is CVE-2021-40407?: CVE-2021-40407 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-40407 being actively exploited?: Yes. CVE-2021-40407 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-12-18, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-40407?: CVE-2021-40407 affects Reolink Rlc-410w Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40407?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-40407 have an EU (EUVD) identifier?: Yes. CVE-2021-40407 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-27584. It is also flagged as exploited in the EUVD (since 2024-12-18).
When was CVE-2021-40407 published?: CVE-2021-40407 was published on 2022-01-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:reolink:rlc-410w_firmware:3.0.0.136_20121102:*:*:*:*:*:*:*

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