A cross-site request forgery vulnerability in the HTTP daemon of the Zyxel ARMOR Z1/Z2 firmware could allow an attacker to execute arbitrar…

published 2022-02-22 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33931

cvss: 8.0; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits: 0; none known

A cross-site request forgery vulnerability in the HTTP daemon of the Zyxel ARMOR Z1/Z2 firmware could allow an attacker to execute arbitrary commands if they coerce or trick a local user to visit a compromised website with malicious scripts.

Patch / fix

fixed in 1

zyxel nbg6817_firmware 1.00\(abcs.11\)c0

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.0	CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

Zyxel ARMOR Z2 (NBG6817) firmware
Zyxel ARMOR Z1 (NBG6816) firmware

Classification

Weakness

CWE-352 Cross-Site Request Forgery

References

zyxel.com /support/forgery-vulnerabilities-of-select-Armor-home-routers.shtml
vendor-advisory

Sources

CVE List CVE-2021-4030
NVD CVE-2021-4030

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary