How severe is CVE-2021-40407?

CVE-2021-40407 has a CVSS score of 7.2/10, rated HIGH. Immediate patching is strongly recommended.

Which products 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 patch CVE-2021-40407?

No patch has shipped for CVE-2021-40407 yet — track the reolink rlc-410w firmware advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2021-40407 across my infrastructure?

Inventory every reolink rlc-410w firmware deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

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

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2021-40407?

O3 detects and blocks CVE-2021-40407 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

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 47.9%, 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.

Which products and versions are affected by CVE-2021-40407?

CVE-2021-40407 affects reolink rlc-410w firmware (1 version, e.g. 3.0.0.136_20121102). Check the affected-products list on this page against your deployed version to confirm 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 June 17, 2026. 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·Added 2024-12-18 — agencies required to remediate by 2025-01-08

CVE-2021-40407

HIGH

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

Jun 17, 2026

Affected

0 pkgs

Patched

None yet

Exploits

2 known

EPSS Exploitation Probability

via FIRST.org ↗

47.9%probability of exploitation in next 30 days

High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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

Vendor / appliance

Detect
Inventory every reolink rlc-410w firmware deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2021-40407 yet — track the reolink rlc-410w firmware advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2021-40407 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2021-40407. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2021-40407 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2021-40407 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVE-2021-40407

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2021-40407 being exploited in your environment?