Security readout for executives and security teams
Plain-English summary
CVE-2018-21153 is a high-severity pre-authentication buffer overflow in many NETGEAR gateways, routers, and extenders. An attacker does not need credentials or user interaction. The CVSS vector limits reachability to an adjacent network, but successful exploitation could compromise confidentiality, integrity, and availability of the device.
Executive priority
Prioritize remediation for affected devices in offices, shared networks, and environments with guest or contractor network access. Treat this as a high-priority infrastructure hygiene issue, especially for older NETGEAR equipment still operating below fixed firmware levels.
Technical view
The CVE record describes an unauthenticated buffer overflow affecting listed NETGEAR models before specific firmware versions, with CVSS 3.0 score 8.8. The vector is AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating low complexity, no privileges, no user interaction, adjacent-network reachability, and high CIA impact.
Likely exposure
Exposure is most likely where named NETGEAR devices remain deployed with firmware older than the fixed versions listed in the CVE record or NETGEAR advisory. Internet exposure is not established by the supplied vector, which says adjacent network.
Exploitation context
The supplied sources do not show CISA KEV listing or active exploitation. Risk is still meaningful because exploitation is unauthenticated, low-complexity, and could fully impact device security if an attacker is on the adjacent network.
Researcher notes
The CVE metadata lists many models and fixed-version thresholds, but does not provide CWE details, proof-of-concept status, or exploit mechanics. The CVSS adjacent-network vector should guide exposure analysis; do not assume remote internet exploitability from the supplied sources alone.
Mitigation direction
- Identify any affected NETGEAR models in inventory.
- Upgrade firmware to the fixed version or later listed for each model.
- Review the NETGEAR advisory for model-specific guidance.
- Reduce untrusted access to adjacent networks where these devices reside.
Validation and detection
- Compare device model and firmware version against the CVE affected list.
- Confirm firmware is at or above the fixed version for that model.
- Check network placement for adjacent-network access by untrusted users.
- Document exceptions where devices cannot be upgraded immediately.
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-2018-21153 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/000059480/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Gateways-Routers-and-Extenders-PSV-2017-3136CVE 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.