Security readout for executives and security teams
Plain-English summary
CVE-2018-21186 is a NETGEAR router and gateway flaw where a logged-in administrator could trigger a stack-based buffer overflow. The impact could be serious on affected devices, but exploitation requires authenticated access and an adjacent-network position, limiting broad internet-scale risk.
Executive priority
Treat this as a moderate-priority network hygiene issue. Prioritize internet-facing or broadly reachable management interfaces, shared-admin environments, and older devices that may no longer receive routine operational attention.
Technical view
The CVE describes a post-authentication stack-based buffer overflow affecting multiple NETGEAR models before specified firmware versions. CVSS 3.0 is 6.8 with adjacent attack vector, low complexity, high privileges required, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely in environments still running the listed NETGEAR models below the fixed firmware versions, especially where administrative access is reachable from local or adjacent networks.
Exploitation context
The source bundle does not show KEV listing or cited active exploitation. The vulnerability requires authenticated high-privilege access, so stolen, weak, or shared administrator credentials would materially increase risk.
Researcher notes
Key constraints are post-authentication and adjacent-network access. The CVE source names affected model/version thresholds, but provides no CWE mapping and no evidence of active exploitation in the supplied bundle.
Mitigation direction
- Inventory listed NETGEAR models and record firmware versions.
- Upgrade affected devices to the fixed firmware versions or later.
- Restrict administrative interfaces to trusted management networks only.
- Review administrator accounts and remove weak or shared credentials.
- Check NETGEAR advisory guidance for model-specific instructions.
Validation and detection
- Compare each device model and firmware against the CVE version list.
- Confirm remote administration is disabled unless explicitly required.
- Verify admin access is limited to trusted internal networks.
- Review router logs for unexpected administrative changes.
- Document any unsupported devices requiring replacement or isolation.
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-2018-21186 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/000055172/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2609CVE 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.