What is CVE-2021-4039?

CVE-2021-4039 is a critical-severity vulnerability in Zyxel Nwa1100-nh Firmware, classified under OS Command Injection. CVSS score: 9.8/10. Published 2022-03-01.

How severe is CVE-2021-4039?

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

Is CVE-2021-4039 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Zyxel Nwa1100-nh Firmware

CVE-2021-4039

A command injection vulnerability in the web interface of the Zyxel NWA-1100-NH firmware could allow an attacker to execute arbitrary OS commands on the device.

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.717 (98.8th percentile) — read the EPSS interpretation.

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.

Affected products

Zyxel Nwa1100-nh Firmware — versions 2.12(AASI.0)C0

Weakness classification (CWE)

CWE-78 — OS Command Injection

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

www.zyxel.com/support/OS-command-injection-vulnerability-of-NWA1100-NH-access-p… (x_refsource_CONFIRM)
packetstormsecurity.com/files/166752/Zyxel-NWA-1100-NH-Command-Injection.html (x_refsource_MISC)

Frequently asked questions

What is CVE-2021-4039?: CVE-2021-4039 is a critical-severity vulnerability in Zyxel Nwa1100-nh Firmware, classified under OS Command Injection. CVSS score: 9.8/10. Published 2022-03-01.
How severe is CVE-2021-4039?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-4039 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.