Security readout for executives and security teams
Plain-English summary
CVE-2018-21093 is a NETGEAR firmware flaw affecting multiple routers, extenders, modem routers, and Orbi satellites. The issue is described as a pre-authentication stack-based buffer overflow. Organizations using listed models below the fixed firmware versions should treat it as a meaningful infrastructure exposure, especially for unmanaged network edge devices.
Executive priority
Prioritize as a moderate remediation item for network edge hardware. It is not KEV-listed in the provided data, but older exposed or unmanaged NETGEAR devices can create avoidable business risk.
Technical view
The CVE describes a stack-based buffer overflow in specified NETGEAR device firmware versions. The record lists CVSS 3.0 score 6.4, severity medium, with high confidentiality and integrity impact and low availability impact. The affected-version evidence is model-specific and based on NETGEAR fixed firmware thresholds.
Likely exposure
Exposure is limited to organizations or users running the listed NETGEAR models on firmware older than the fixed versions. The source bundle does not identify affected CPEs generically, so validation must be model and firmware specific.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. The description says unauthenticated pre-authentication overflow, but the CVSS vector includes PR:H; treat that inconsistency as an evidence limitation.
Researcher notes
The most important research point is source inconsistency: the narrative says unauthenticated pre-authentication, while the CVSS vector includes PR:H and AV:A. Do not infer remote internet exploitation from the bundle alone.
Mitigation direction
- Inventory listed NETGEAR router, extender, modem router, and Orbi satellite models.
- Upgrade affected devices to the NETGEAR fixed firmware version or later.
- Check the NETGEAR advisory for exact model-specific firmware guidance.
- Replace devices that cannot run a fixed firmware release.
Validation and detection
- Compare device model numbers against the affected model list.
- Record each device firmware version from administrative inventory or device management.
- Verify firmware is at or above the fixed version for that model.
- Document any unsupported or unreachable devices for replacement planning.
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.
CVE-2018-21093 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
- 6.4 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AC:L/AV:A/A:L/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:L/C:H/I:H/PR:H/S:U/UI:N0.95.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.4MediumVector: CVSS:3.0/AC:L/AV:A/A:L/C:H/I:H/PR:H/S:U/UI:N
Source materials
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.