Security readout for executives and security teams
Plain-English summary
CVE-2018-21190 is a post-authentication stack buffer overflow affecting several NETGEAR routers and gateways. An attacker needs valid device access and adjacent-network reachability, but successful exploitation could seriously affect confidentiality, integrity, and availability. The source bundle does not report active exploitation.
Executive priority
Treat this as a moderate-priority infrastructure hygiene issue. It is not sourced as actively exploited, but affected routers are boundary devices and successful compromise could be high impact. Patch or retire confirmed vulnerable devices during the next controlled maintenance window.
Technical view
The CVE describes a stack-based buffer overflow reachable by an authenticated user on specific NETGEAR D-series, R-series, WNDR, and WNR devices before listed firmware versions. CVSS v3.0 is 6.8 with adjacent attack vector, low complexity, high privileges required, no user interaction, and high C/I/A impact.
Likely exposure
Exposure is most likely where affected NETGEAR models remain on firmware older than the fixed versions listed in the CVE and NETGEAR advisory. Risk is constrained by the adjacent-network and high-privilege requirements, but unmanaged small-office, branch, or home-office routers may remain vulnerable.
Exploitation context
The provided sources do not show KEV listing or active exploitation. The vulnerability is not described as unauthenticated or internet-routable in the bundle. Assessment should focus on authenticated administrative access paths and whether vulnerable firmware is still deployed.
Researcher notes
The bundle gives affected models, fixed firmware thresholds, CVSS vector, and vendor advisory, but little detail about the vulnerable component or trigger path. Avoid assuming unauthenticated or remote internet exploitation. Validation should be version-based unless vendor guidance provides a safe diagnostic method.
Mitigation direction
- Upgrade affected NETGEAR devices to the fixed firmware versions listed in the advisory.
- Prioritize devices that support business connectivity, remote offices, or privileged administrative access.
- Check NETGEAR guidance for model-specific update instructions and replacement advice.
- Limit administrative access to trusted users and trusted local management networks.
- Retire affected devices if fixed firmware is unavailable or cannot be validated.
Validation and detection
- Inventory NETGEAR D6100, D7800, R6100, R7500, R7800, R9000, WNDR, and WNR models.
- Compare installed firmware against the fixed versions named in the CVE description.
- Confirm administrative accounts are limited to authorized personnel.
- Verify management interfaces are not broadly reachable from untrusted adjacent networks.
- 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.
CVE-2018-21190 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/000055167/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2605CVE 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.