Security readout for executives and security teams
Plain-English summary
This is a post-authentication stack overflow in several older NETGEAR routers, gateways, and extenders. The source data rates it medium severity but with high confidentiality, integrity, and availability impact if an authenticated high-privilege adjacent attacker can reach the device.
Executive priority
Treat this as a targeted remediation item for legacy network edge equipment. It is not evidenced as actively exploited here, but successful compromise could affect network availability and device control.
Technical view
CVE-2018-21163 affects listed NETGEAR firmware before specified fixed versions. CVSS 3.0 is 6.8: adjacent-network attack vector, low complexity, high privileges required, no user interaction, unchanged scope, and high C/I/A impact. No CWE is provided in the bundle.
Likely exposure
Exposure is likely limited to organizations still running the named legacy NETGEAR DGN, EX, R, WN2500RPv2, or WNDR3400v3 devices below the fixed firmware versions listed by NETGEAR and CVE sources.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation evidence. The attack is post-authentication and adjacent-network per CVSS, so risk depends on who has privileged device access and local network reachability.
Researcher notes
Key constraints are post-authentication, high privileges, adjacent-network access, and high C/I/A impact. The source bundle names affected models and fixed firmware thresholds but provides no exploit detail, CWE mapping, or observed exploitation evidence.
Mitigation direction
- Inventory affected NETGEAR models and record current firmware versions.
- Update each affected device to the fixed firmware version or later.
- Restrict administrative access to trusted users and trusted network segments.
- Check NETGEAR guidance for model-specific upgrade or replacement direction.
- Replace unsupported devices if fixed firmware is unavailable in your environment.
Validation and detection
- Compare device model and firmware against the affected version list.
- Confirm updated firmware is at or above NETGEAR's listed fixed version.
- Review device administrator accounts for unnecessary privileged access.
- Verify management access is not broadly reachable from untrusted networks.
- Document remaining exceptions, compensating controls, and replacement timelines.
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-2018-21163 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/000055196/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-Gateways-and-Extenders-PSV-2017-0308CVE 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.