What is CVE-2018-21133?

CVE-2018-21133 is a critical-severity vulnerability in NETGEAR Wac505, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2020-04-23.

How severe is CVE-2018-21133?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in NETGEAR Wac505

CVE-2018-21133

Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects WAC505 before 5.0.0.17 and WAC510 before 5.0.0.17.

Vulnerability class: Buffer Overflow

Published 2020-04-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.014 (70.7th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 70.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.014 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

kb.netgear.com/000060227/Security-Advisory-for-Pre-Authentication-Stack-Overflo… (Vendor Advisory)

Frequently asked questions

What is CVE-2018-21133?: CVE-2018-21133 is a critical-severity vulnerability in NETGEAR Wac505, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2020-04-23.
How severe is CVE-2018-21133?: Critical severity. CVSS v3 base score is 9.8 out of 10.