Security readout for executives and security teams
Plain-English summary
CVE-2021-40407 lets an attacker with high privileges abuse a Reolink camera network settings API so the device runs unintended operating-system commands. The issue is critical because successful compromise can affect confidentiality, integrity, and availability. CISA lists it in KEV, so treat relevant devices as exposed to real-world exploitation risk.
Executive priority
Prioritize affected cameras where management access is exposed beyond trusted administrators. KEV status means this should be handled as an active risk, not just a theoretical bug. If affected devices cannot be updated promptly, isolate or remove them from sensitive networks.
Technical view
Talos describes OS command injection in Reolink RLC-410W v3.0.0.136_20121102 DDNS handling. The SetDdns API domain parameter flows into ddns->domain without proper validation, based on DDNS type. CVSS 3.0 is 9.1: network exploitable, low complexity, high privileges, no user interaction, changed scope, high CIA impact.
Likely exposure
Exposure is most likely where Reolink RLC-410W cameras run firmware v3.0.0.136_20121102 and their management/API surface is reachable. Internet-facing or broadly reachable management interfaces raise urgency. The source bundle does not identify other affected products or versions.
Exploitation context
CISA KEV inclusion supports known exploitation. The Talos description says an attacker can trigger the flaw with an HTTP request, but CVSS indicates high privileges are required. The supplied sources do not provide exploit prevalence, campaign details, or a public exploit timeline.
Researcher notes
The key weakness is CWE-78 command injection through insufficient validation of the DDNS domain parameter. Evidence is specific to the named Reolink firmware. Do not broaden scope without vendor confirmation. Public sources provided here do not name a definitive patch level.
Mitigation direction
- Inventory Reolink RLC-410W cameras and record firmware versions.
- Remove camera management interfaces from internet and untrusted network access.
- Restrict API access to trusted admin networks or VPN paths only.
- Check Reolink, Talos, and CISA guidance for vendor-approved updates or mitigations.
- Review and rotate administrative credentials for exposed camera management accounts.
- Monitor for unexpected DDNS configuration changes or suspicious management activity.
Validation and detection
- Confirm whether any assets match Reolink RLC-410W v3.0.0.136_20121102.
- Verify the management interface is not reachable from the public internet.
- Review access controls for the SetDdns/API management path.
- Check logs or configuration history for unexpected DDNS domain changes.
- Confirm remediation status against vendor guidance and asset inventory records.
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-2021-40407 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
- Yes
- 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.
CISA KEV status
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
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40407CVE reference · government-resource
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.
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.