How severe is CVE-2021-40407?

No CVSS score has been assigned to CVE-2021-40407 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2021-40407?

Affected package information for CVE-2021-40407 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-40407?

No fixed release is recorded for CVE-2021-40407 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2021-40407 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2021-40407 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2021-40407 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2021-40407, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-40407?

CVE-2021-40407 has an EPSS (Exploit Prediction Scoring System) score of 47.6%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2021-40407 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-40407 (Reolink RLC-410W IP Camera OS Command Injection Vulnerability ) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2024-12-18. CISA required all US federal civilian agencies to remediate this vulnerability by 2025-01-08. The required action was: The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization if a current mitigation is unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-40407?

CVE-2021-40407 is classified as OS Command Injection (CWE-78). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-40407 published, and has it been updated?

CVE-2021-40407 was published on January 28, 2022 and was last updated on October 21, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV · ACTIVELY EXPLOITED

CVE-2021-40407

CVE-2021-40407 is a OS Command Injection vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2024-12-18) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

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…

Published

Jan 28, 2022

Updated

Oct 21, 2025

Affected

1 product

Patched

See advisory

Exploits

2 known

Exploitation data as of Oct 21, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2024-12-18. Federal agencies were required to remediate by 2025-01-08.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2021-40407.

EPSS Exploitation Probability

via FIRST.org ↗

47.6%probability of exploitation in next 30 days

High Risk0.00%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

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.

Affected Products

1 product · 1 configurations

rlc-410w firmwarereolink

1 version

3.0.0.136_20121102

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An OS command injection vulnerability exists in the device network setti…

talosintelligence.comNVDFeb 2022

An OS command injection vulnerability exists in the device network setti…

cisa.govCISADec 2024

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2021-40407 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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