Security readout for executives and security teams
Plain-English summary
CVE-2018-21191 is a NETGEAR router and gateway flaw where a highly privileged authenticated user could trigger a stack-based buffer overflow. The business risk is mainly for exposed or poorly controlled device administration paths, not broad unauthenticated internet compromise based on the supplied sources.
Executive priority
Treat this as a targeted infrastructure hygiene issue. Prioritize remediation where affected devices manage sensitive networks, have shared administrator credentials, or expose management access to contractors, guests, or untrusted local users.
Technical view
The CVE describes a post-authentication stack-based buffer overflow affecting specific NETGEAR D6100, R6100, R7800, WNDR, and WNR firmware versions. CVSS 3.0 is 6.8 with adjacent network access, low attack complexity, high privileges required, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to organizations still running the listed NETGEAR models below the fixed firmware versions, especially where router administration is reachable by untrusted local or wireless users.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The vulnerability requires authentication with high privileges and adjacent network access per CVSS, but successful exploitation could have serious device-level impact.
Researcher notes
The provided affected CPE data is empty, so rely on the CVE description and NETGEAR advisory for product matching. Do not assume unauthenticated or internet-routable exploitation from the supplied evidence.
Mitigation direction
- Upgrade affected NETGEAR devices to the fixed firmware versions or later.
- Review the NETGEAR advisory for model-specific firmware guidance.
- Restrict device administration to trusted management networks.
- Disable unnecessary remote or wireless administrative access where possible.
- Audit administrator accounts and remove unnecessary privileged access.
Validation and detection
- Inventory NETGEAR D6100, R6100, R7800, WNDR, and WNR devices.
- Compare installed firmware against the affected versions listed in the CVE description.
- Confirm administration interfaces are not reachable from untrusted networks.
- Review logs for unexpected administrative access or configuration changes.
- Document remediation status for each affected device.
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-2018-21191 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/000055166/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2604CVE 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.