Security readout for executives and security teams
Plain-English summary
Certain NETGEAR routers and gateways have a stack overflow flaw reachable after authentication. Risk is concentrated in older firmware on listed models. It is not an unauthenticated internet-wide issue, but successful exploitation could seriously affect device confidentiality, integrity, and availability.
Executive priority
Treat as a scheduled remediation item for affected legacy NETGEAR devices, with higher urgency where admin interfaces are broadly reachable or credentials are weak. Do not defer indefinitely, because successful exploitation could have high security impact on network edge equipment.
Technical view
CVE-2018-21196 is a post-authentication stack-based buffer overflow affecting D6100, R6100, R7800, R9000, WNDR3700v4, WNDR4300, and WNR2000v5 below specified firmware versions. CVSS 3.0 is 6.8 with adjacent-network attack vector, low complexity, high privileges required, no user interaction, and high CIA impact.
Likely exposure
Organizations are exposed if they still operate the named NETGEAR models on firmware older than the fixed versions listed in the CVE. Exposure is most relevant where administrative access is reachable from internal, guest, or shared networks.
Exploitation context
The source bundle does not cite active exploitation, and the CVE is not listed as KEV. The vulnerability requires authenticated access with high privileges and adjacent-network reachability, which reduces broad opportunistic risk but leaves concern for compromised credentials or insider access.
Researcher notes
Evidence identifies affected models and firmware thresholds but does not provide technical exploit details, CWE mapping, or confirmed exploitation. Validation should focus on firmware/version checks, management-plane exposure, and whether the device is still supportable under NETGEAR guidance.
Mitigation direction
- Upgrade affected NETGEAR devices to the fixed firmware versions or later.
- Check the NETGEAR advisory for model-specific update instructions.
- Remove or replace devices that cannot run supported fixed firmware.
- Limit router administration access to trusted management networks.
- Review administrative accounts and remove unnecessary privileged users.
Validation and detection
- Inventory NETGEAR router and gateway models in use.
- Compare installed firmware against the CVE's fixed version thresholds.
- Confirm administrative interfaces are not reachable from untrusted networks.
- Check the NETGEAR advisory for any additional device-specific notes.
- Record remediation status for each affected model and firmware version.
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-2018-21196 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/000055153/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2599CVE 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.