What is CVE-2021-20640?

CVE-2021-20640 is a medium-severity vulnerability in Logitec Corporation Lan-W300n/pgrb, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.8/10. Published 2021-02-12.

How severe is CVE-2021-20640?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Buffer overflow in Logitec Corporation Lan-W300n/pgrb

CVE-2021-20640

Buffer overflow vulnerability in LOGITEC LAN-W300N/PGRB allows an attacker with administrative privilege to execute an arbitrary OS command via unspecified vectors.

Vulnerability class: Buffer Overflow

Published 2021-02-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (44.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.6% 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: 0.006 · change: +0.000

Affected products

Logitec Corporation Lan-W300n/pgrb — versions LAN-W300N/PGRB
Logitech Lan-W300n\/pgrb
Logitech Lan-W300n\/pgrb Firmware

Weakness classification (CWE)

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

References

www.elecom.co.jp/news/security/20210126-01/ (Vendor Advisory)
jvn.jp/en/jp/JVN96783542/index.html (Third Party Advisory)
lists.apache.org/thread.html/rc1778b38e74b5b6142414d57623bd55b023a72361f4228367… (mailing-list)

Frequently asked questions

What is CVE-2021-20640?: CVE-2021-20640 is a medium-severity vulnerability in Logitec Corporation Lan-W300n/pgrb, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.8/10. Published 2021-02-12.
How severe is CVE-2021-20640?: Medium severity. CVSS v3 base score is 6.8 out of 10.