Security readout for executives and security teams
Plain-English summary
CVE-2018-21220 is a high-severity pre-authentication buffer overflow in several NETGEAR routers and gateways. An unauthenticated attacker on an adjacent network could potentially cause serious confidentiality, integrity, and availability impact on devices running affected firmware versions.
Executive priority
Prioritize remediation for affected NETGEAR devices still in production, especially those serving business networks or guest wireless environments. Treat this as a high-priority infrastructure hygiene issue rather than confirmed emergency exploitation based on the supplied evidence.
Technical view
The CVE describes a buffer overflow affecting specified NETGEAR D-series, R-series, WNDR, and WNR devices before listed firmware versions. CVSS 3.0 is 8.8 with adjacent-network attack vector, low complexity, no privileges, no user interaction, and high impact to confidentiality, integrity, and availability.
Likely exposure
Exposure is most likely where older affected NETGEAR routers or gateways remain deployed below the fixed firmware versions. The CVSS vector indicates adjacent-network reachability, so local, wireless, or nearby network access is the key concern from the provided data.
Exploitation context
The supplied sources do not show CISA KEV listing or confirmed active exploitation. The issue is still important because it is pre-authentication, low-complexity, and affects network edge devices, but exploit availability and exact attack interface are not established in the bundle.
Researcher notes
The source bundle gives strong affected-version and CVSS data but limited root-cause detail. No CWE, exploit status, or interface-level specifics are provided. Validation should stay version-based unless NETGEAR guidance or device testing provides more detail.
Mitigation direction
- Inventory NETGEAR models against the affected device and firmware list.
- Update affected devices to the listed fixed firmware version or later.
- Check the NETGEAR advisory for model-specific firmware guidance.
- Replace devices that cannot receive supported fixed firmware.
- Restrict untrusted adjacent-network access while remediation is pending.
Validation and detection
- Record each device model and current firmware version.
- Compare firmware versions against the CVE affected-version list.
- Confirm upgraded devices report the fixed version or later.
- Review network segmentation around affected router and gateway access.
- Track remediation evidence in vulnerability management 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.
CVE-2018-21220 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
- High
- CVSS
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/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:N/S:U/UI:N2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/S:U/UI:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.netgear.com/000055117/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2481CVE 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.