What is CVE-2021-34236?

CVE-2021-34236 is a critical-severity vulnerability in NETGEAR R8000, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2022-09-08.

How severe is CVE-2021-34236?

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

Buffer overflow in NETGEAR R8000

CVE-2021-34236

Buffer Overflow in Netgear R8000 Router with firmware v1.0.4.56 allows remote attackers to execute arbitrary code or cause a denial-of-service by sending a crafted POST to '/bd_genie_create_account.cgi' with a sufficiently long parameter 'register_country'.

Vulnerability class: Buffer Overflow

Published 2022-09-08 · 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: 0.015 (72.8th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.015 · change: +0.003

Affected products

NETGEAR R8000
NETGEAR R8000 Firmware — versions 1.0.4.56

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/Davidteeri/Bug-Report/blob/main/netgear-8000.md (Broken Link)
github.com/advisories/GHSA-vfq9-7wg3-4mjx (Third Party Advisory)

Frequently asked questions

What is CVE-2021-34236?: CVE-2021-34236 is a critical-severity vulnerability in NETGEAR R8000, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2022-09-08.
How severe is CVE-2021-34236?: Critical severity. CVSS v3 base score is 9.8 out of 10.