Security readout for executives and security teams
Plain-English summary
CVE-2018-21227 is a post-authentication command injection flaw in specific NETGEAR routers and gateways running older firmware. A highly privileged authenticated attacker on an adjacent network could potentially run operating-system commands on the device. The source bundle does not show CISA KEV listing or active exploitation evidence.
Executive priority
Treat as a medium-priority router remediation item. Prioritize internet-edge, business-critical, or shared-network devices, but urgency is reduced by the high-privilege and adjacent-network requirements and lack of exploitation evidence in sources.
Technical view
The CVE record describes authenticated command injection affecting multiple NETGEAR models before named fixed firmware versions. CVSS v3.0 is 6.8 with adjacent-network access, low complexity, high privileges required, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely in organizations or homes still running the listed NETGEAR models below the fixed firmware versions, especially where router administration is accessible to more users than necessary.
Exploitation context
Sources support a post-authentication issue requiring high privileges and adjacent-network access. The bundle provides no exploit details, no public exploitation confirmation, and KEV is false, so active exploitation should not be assumed.
Researcher notes
The provided affected CPE data is not populated, so model and firmware matching must use the CVE description and NETGEAR advisory. Do not infer additional affected products beyond the listed models and pre-fixed firmware versions.
Mitigation direction
- Upgrade affected NETGEAR devices to the listed fixed firmware version or later.
- Review NETGEAR advisory guidance for model-specific firmware availability.
- Limit router administrative access to authorized administrators only.
- Retire affected models if fixed firmware is unavailable or unsupported.
Validation and detection
- Inventory NETGEAR D7800, R6400v2, R6700, R6900, R6900P, R7000, R7000P, R7500v2, R7800, R9000, WNDR4300v2, and WNDR4500v3.
- Compare installed firmware against the fixed versions listed in the CVE description.
- Confirm administrative access is restricted to expected privileged users.
- Document devices that cannot be upgraded and track compensating controls.
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-2018-21227 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/000055109/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-Routers-and-Gateways-PSV-2017-0737CVE 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.