Security readout for executives and security teams
Plain-English summary
CVE-2021-40408 is a critical command-injection flaw in Reolink RLC-410W firmware v3.0.0.136_20121102. A highly privileged user could abuse DDNS network settings input to make the device run operating-system commands, risking full compromise of affected cameras.
Executive priority
Treat as high-priority for any exposed or broadly administered camera fleet. The privilege requirement lowers opportunistic risk, but successful abuse could give attackers full device control and affect confidentiality, integrity, and availability.
Technical view
The flaw is CWE-78 OS command injection in the SetDdns API path. The ddns->username value, sourced from the userName parameter, is not properly validated. CVSS 3.0 is 9.1: network attack vector, low complexity, high privileges required, no user interaction, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to Reolink RLC-410W devices on firmware v3.0.0.136_20121102 where highly privileged users can reach the network settings or SetDdns API. The provided CVE affected-product metadata is incomplete, so inventory confirmation is essential.
Exploitation context
The provided sources do not show active exploitation, and this CVE is not marked KEV. Exploitation requires high privileges but is network-reachable and low-complexity once an attacker has privileged access to the device management surface.
Researcher notes
Evidence points specifically to DDNS username handling in SetDdns on RLC-410W v3.0.0.136_20121102. The source bundle does not provide a fixed version, exploit-in-the-wild evidence, or complete CPE data. Avoid broad product assumptions without vendor confirmation.
Mitigation direction
- Identify Reolink RLC-410W devices and confirm firmware version.
- Check Reolink and Talos guidance for fixed firmware or official mitigation.
- Restrict camera management/API access to trusted admin networks or VPN.
- Review privileged accounts and remove unnecessary administrative access.
- Monitor affected devices for unexpected configuration changes or command-execution indicators.
Validation and detection
- Confirm whether any RLC-410W runs firmware v3.0.0.136_20121102.
- Verify who can access the device network settings and SetDdns API.
- Check whether DDNS configuration changes are logged or centrally monitored.
- Confirm management interfaces are not exposed to untrusted networks.
- Document vendor firmware status before closing the finding.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-40408 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H2.36Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
9.1CriticalVector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1424CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.