What is CVE-2021-20739?

CVE-2021-20739 is a high-severity vulnerability in Elecom Wrc-300febk, classified under OS Command Injection. CVSS score: 8.8/10. Published 2021-07-07.

How severe is CVE-2021-20739?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in Elecom Wrc-300febk

CVE-2021-20739

WRC-300FEBK, WRC-F300NF, WRC-733FEBK, WRH-300RD, WRH-300BK, WRH-300SV, WRH-300WH, WRH-H300WH, WRH-H300BK, WRH-300BK-S, and WRH-300WH-S all versions allows an unauthenticated network-adjacent attacker to execute an arbitrary OS command via unspecified vectors.

Vulnerability class: Command Injection (OS Command Injection)

Published 2021-07-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (41.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.3% 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

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

www.elecom.co.jp/news/security/20210706-01/ (Vendor Advisory)
jvn.jp/en/vu/JVNVU94260088/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-20739?: CVE-2021-20739 is a high-severity vulnerability in Elecom Wrc-300febk, classified under OS Command Injection. CVSS score: 8.8/10. Published 2021-07-07.
How severe is CVE-2021-20739?: High severity. CVSS v3 base score is 8.8 out of 10.