Security readout for executives and security teams
Plain-English summary
This issue affects specific older NETGEAR routers and gateways. A person who already has high-privilege authenticated access could trigger a stack-based buffer overflow, potentially causing serious compromise of the device. It is not listed as actively exploited in CISA KEV, but exposed or poorly governed admin access increases business risk.
Executive priority
Treat this as a targeted network-device remediation item. Prioritize internet-edge or sensitive-site routers first, especially where admin access is shared or weakly controlled. It is not currently KEV-listed, but outdated router firmware can create disproportionate operational risk.
Technical view
CVE-2018-21177 is a post-authentication stack-based buffer overflow affecting D6100, R6100, R7800, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, and WNR2000v5 before specified firmware versions. CVSS 3.0 is 6.8 with adjacent-network access, low complexity, high privileges required, no user interaction, and high CIA impact.
Likely exposure
Exposure is limited to organizations still running the named NETGEAR models below the fixed firmware versions. The CVSS vector indicates adjacent-network reachability and high privileges are required, so risk depends heavily on admin account control and management-plane accessibility.
Exploitation context
The provided sources do not show active exploitation, and the CVE is not in KEV. Exploitation requires an authenticated high-privilege user on an adjacent network, but successful abuse could have high confidentiality, integrity, and availability impact on the device.
Researcher notes
The bundle provides no CWE assignment beyond the stack-based overflow description and no exploit details. Keep assessment scoped to the listed models and firmware thresholds. Do not infer impact for other NETGEAR products without additional vendor evidence.
Mitigation direction
- Inventory for the affected NETGEAR models listed in the advisory.
- Update each affected device to the named fixed firmware version or later.
- Check NETGEAR guidance for devices that cannot be updated.
- Retire or replace devices that cannot be brought to a supported firmware level.
Validation and detection
- Compare device model and firmware against the affected-version list.
- Confirm updated devices run the fixed firmware version or later.
- Review which users have high-privilege router administration access.
- Verify management access is not exposed beyond intended trusted networks.
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-2018-21177 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/000055181/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2622CVE 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.