What is CVE-2021-3511?

CVE-2021-3511 is a medium-severity vulnerability in Buffalo Bhr-4grv. CVSS score: 4.3/10. Published 2021-04-28.

How severe is CVE-2021-3511?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Buffalo Bhr-4grv

CVE-2021-3511

Disclosure of sensitive information to an unauthorized user vulnerability in Buffalo broadband routers (BHR-4GRV firmware Ver.1.99 and prior, DWR-HP-G300NH firmware Ver.1.83 and prior, HW-450HP-ZWE firmware Ver.1.99 and prior, WHR-300HP firmware Ver.1.99 and prior, WHR-300 firmware Ver.1.99 and prior, WHR-G301N firmware Ver.1.86 and prior, WHR-HP-G300N firmware Ver.1.99 and prior, WHR-HP-GN firmware Ver.1.86 and prior, WPL-05G300 firmware Ver.1.87 and prior, WZR-450HP-CWT firmware Ver.1.99 and prior, WZR-450HP-UB firmware Ver.1.99 and prior, WZR-HP-AG300H firmware Ver.1.75 and prior, WZR-HP-G300NH firmware Ver.1.83 and prior, WZR-HP-G301NH firmware Ver.1.83 and prior, WZR-HP-G302H firmware Ver.1.85 and prior, WZR-HP-G450H firmware Ver.1.89 and prior, WZR-300HP firmware Ver.1.99 and prior, WZR-450HP firmware Ver.1.99 and prior, WZR-600DHP firmware Ver.1.99 and prior, WZR-D1100H firmware Ver.1.99 and prior, FS-HP-G300N firmware Ver.3.32 and prior, FS-600DHP firmware Ver.3.38 and prior, FS-R600DHP firmware Ver.3.39 and prior, and FS-G300N firmware Ver.3.13 and prior) allows remote unauthenticated attackers to obtain information such as configuration via unspecified vectors.

Published 2021-04-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (41.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

References

www.buffalo.jp/news/detail/20210427-01.html (Vendor Advisory)
jvn.jp/en/vu/JVNVU99235714/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-3511?: CVE-2021-3511 is a medium-severity vulnerability in Buffalo Bhr-4grv. CVSS score: 4.3/10. Published 2021-04-28.
How severe is CVE-2021-3511?: Medium severity. CVSS v3 base score is 4.3 out of 10.