Security readout for executives and security teams
Plain-English summary
This CVE affects multiple older NETGEAR routers, gateways, and extenders. An unauthenticated attacker on an adjacent network could trigger a stack-based buffer overflow before authentication. The impact is high because confidentiality, integrity, and availability are rated high, but the source bundle does not show known active exploitation.
Executive priority
Prioritize remediation where these devices protect business networks, remote offices, or shared environments. The issue is high impact and unauthenticated, but urgency should be driven by whether affected models still exist and whether untrusted users can reach them.
Technical view
CVE-2018-21205 is a pre-authentication stack-based buffer overflow in specific NETGEAR device firmware versions. CVSS 3.0 is 8.8 with AV:A, AC:L, PR:N, UI:N, and high C/I/A impact. The affected list includes D7800, EX2700, R-series, WN2000/WN3000/WN3100 repeaters, and WNDR models below named firmware versions.
Likely exposure
Exposure is most likely in environments still using the listed NETGEAR models with firmware older than the fixed versions. The CVSS vector indicates adjacent-network exposure, so risk is highest where untrusted users can reach the device network segment.
Exploitation context
The provided sources describe unauthenticated pre-authentication impact but do not include exploit code, public exploitation evidence, or CISA KEV listing. Treat exploitation as plausible given the vulnerability class and low complexity, but not confirmed active from the supplied evidence.
Researcher notes
The source bundle names many affected NETGEAR models and fixed firmware thresholds, but the normalized affected CPE data is not populated. Analysis should rely on the advisory and CVE description, not infer additional products or exploit status.
Mitigation direction
- Inventory NETGEAR models listed in the advisory across offices, labs, and remote sites.
- Upgrade affected devices to the fixed firmware version or later named for each model.
- If firmware cannot be updated, check NETGEAR guidance for supported alternatives or replacement direction.
- Restrict access to device management and adjacent network segments to trusted administrators only.
- Retire unsupported or unmanaged devices that cannot be verified or updated.
Validation and detection
- Compare each device model and firmware version against the advisory’s affected-version thresholds.
- Confirm updated devices report firmware at or above the fixed version for that exact model.
- Review network placement for exposed management or untrusted adjacent access paths.
- Check asset records for older repeaters, extenders, and routers outside central IT ownership.
- Document exceptions, compensating controls, and planned replacement dates for unpatched devices.
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-2018-21205 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
- High
- CVSS
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/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:N/S:U/UI:N2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/S:U/UI:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.netgear.com/000055144/Security-Advisory-for-Pre-Authentication-Stack-Overflow-on-Some-Routers-Gateways-and-Extenders-PSV-2017-2568CVE 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.