Security readout for executives and security teams
Plain-English summary
CVE-2018-21146 is an authenticated command injection issue in specific NETGEAR routers and gateways. A valid administrative user on an adjacent network could potentially run commands on the device. Business urgency is moderate: impact can be severe on vulnerable devices, but exploitation requires high privileges and network proximity according to the CVSS vector.
Executive priority
Prioritize remediation for vulnerable devices managing sensitive networks or remote sites. This is not a confirmed actively exploited issue in the provided sources, but compromise of router management can create broad operational and security impact.
Technical view
The CVE describes post-authentication command injection affecting NETGEAR D7800, R7800, R8900, R9000, WNDR4300v2, and WNDR4500v3 before specified firmware versions. CVSS 3.0 is 6.8 with AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H, indicating adjacent-network access, high privileges, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where listed NETGEAR models run vulnerable firmware and their administration interfaces are reachable from local or management networks. The source bundle does not establish internet exposure or affected products beyond the listed models.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. The vulnerability should still be treated seriously because command injection on a router can affect traffic, configuration, and device control if an authenticated attacker reaches the management plane.
Researcher notes
Evidence is limited to the CVE description, CVSS vector, and NETGEAR advisory reference. The bundle does not include CWE mapping, proof-of-concept details, exploit telemetry, or a detailed root-cause description. Avoid assuming additional affected models or exploitability conditions beyond authenticated adjacent access.
Mitigation direction
- Upgrade affected devices to the listed fixed firmware versions or later.
- Review the NETGEAR advisory for model-specific firmware guidance.
- Restrict administration access to trusted management networks only.
- Rotate administrative credentials where shared, weak, or exposed.
- Replace unsupported devices if fixed firmware is unavailable.
Validation and detection
- Inventory NETGEAR D7800, R7800, R8900, R9000, WNDR4300v2, and WNDR4500v3 devices.
- Compare installed firmware with the affected version thresholds in the CVE description.
- Confirm router administration interfaces are not exposed beyond trusted networks.
- Review admin account usage for shared, stale, or unnecessary privileged access.
- Document remediation status per device model and firmware version.
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.
Execution 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-2018-21146 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
- Medium
- CVSS
- 6.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N
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/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N0.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.8MediumVector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.netgear.com/000059487/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-Gateways-and-Routers-PSV-2017-3159CVE reference · x_refsource_CONFIRM
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.