LiveActive security incident?Get immediate response
CVE Record

CVE-2018-21111: Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user.

Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D3600 before 1.0.0.75, D6000 before 1.0.0.75, D6100 before 1.0.0.60, R7800 before 1.0.2.52, R8900 before 1.0.4.2, R9000 before 1.0.4.2, WNDR3700v4 before 1.0.2.102, WNDR4300 before 1.0.2.104, WNDR4300v2 before 1.0.0.58, WNDR4500v3 before 1.0.0.58, and WNR2000v5 before 1.0.0.66.

MediumCVSS 6.8Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This vulnerability affects several NETGEAR routers and modem routers. An already authenticated user could trigger a stack-based buffer overflow, with high confidentiality, integrity, and availability impact in the CVSS data. It is not listed as KEV, and the provided sources do not show active exploitation.

Executive priority

Treat as a moderate priority for network edge hygiene. The bug has severe potential impact, but it requires authenticated high-privilege access and is not identified as actively exploited in the supplied evidence. Prioritize patching exposed or business-critical routers first.

Technical view

CVE-2018-21111 is a post-authentication stack-based buffer overflow affecting listed NETGEAR D-series, R-series, WNDR, and WNR devices before specified firmware versions. CVSS 3.0 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 run firmware older than the fixed versions and allow administrative access from local or adjacent networks. Internet-exposed administration would increase practical risk, but that exposure is not stated in the provided sources.

Exploitation context

The sources describe a post-authentication issue requiring high privileges. KEV status is false, and no cited source in the bundle reports active exploitation or public exploit availability. Evidence is insufficient to assess real-world exploitation beyond the vulnerability description.

Researcher notes

The bundle does not include vulnerable endpoint details, proof-of-concept material, CWE assignment, or indicators of compromise. Validation should focus on model and firmware matching, management-plane exposure, and whether device administration is appropriately restricted.

Mitigation direction

  • Upgrade affected NETGEAR devices to the fixed firmware version or later.
  • Follow the linked NETGEAR security advisory for model-specific guidance.
  • Restrict router administration to trusted management networks only.
  • Remove unnecessary administrator accounts and rotate router administrative credentials.
  • Replace unsupported devices if fixed firmware is unavailable.

Validation and detection

  • Inventory NETGEAR router and modem-router models in use.
  • Compare installed firmware against the fixed versions listed in the CVE description.
  • Confirm administrative interfaces are not broadly reachable.
  • Verify only expected administrative users exist on affected devices.
  • Document remediation status for each affected model.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · low confidence lookup

CVE-2018-21111 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
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

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
6.8CVSS 3.0MediumCVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N0.95.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

6.8Medium
CVSS 3.0 vector shape for CVE-2018-21111Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.