01 Record

CVE-2022-26531

Multiple improper input validation flaws were identified in some CLI commands of Zyxel USG/ZyWALL series firmware versions 4.09 through 4.71, USG FLEX series firmware versions 4.50 through 5.21, ATP

MediumPUBLISHEDCNA: Zyxel

CNA base score6.1 CVSS v3.xCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

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02 Description

Multiple improper input validation flaws were identified in some CLI commands of Zyxel USG/ZyWALL series firmware versions 4.09 through 4.71, USG FLEX series firmware versions 4.50 through 5.21, ATP

03 Exploitation and scoring

Exploitation: Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision: Not assessed by CISA
EPSS probability: 6.17% probability of exploitation activity in the next 30 days.
EPSS percentile: Equal to or higher than the score of 93.2% of scored records. A rank, not a probability.
NVD base score: 7.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD analysis status: Modified. NVD last modified this record on 2026-06-17.
Red Hat severity: No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2022-05-24 00:00Z4 YR AGO

Last updated

2024-08-03 05:03Z2 YR AGO

Reserved

2022-03-07

Assigning CNA

Zyxel

Record state

PUBLISHED

Severity

Medium (CVSS 6.1)

CNA CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Weaknesses

CWE-20Improper Input ValidationClass

Data version

5.1

Document digest

bff02699803acbd9929956974f0b12efd56d817a5d3a2aead2344dc655b950da

05 Affected products

VendorProductVersionsPlatforms

ZyxelUSG/ZyWALL series firmware4.09 through 4.71—

ZyxelUSG FLEX series firmware4.50 through 5.21—

ZyxelATP series firmware4.32 through 5.21—

ZyxelVPN series firmware4.30 through 5.21—

ZyxelNSG series firmware1.00 through 1.33 Patch 4—

ZyxelNXC2500 firmware<= 6.10(AAIG.3)—

ZyxelNAP203 firmware<= 6.25(ABFA.7)—

ZyxelNWA50AX firmware<= 6.25(ABYW.5)—

ZyxelWAC500 firmware<= 6.30(ABVS.2)—

ZyxelWAX510D firmware<= 6.30(ABTF.2)—

06 References

www.zyxel.comhttps://www.zyxel.com/support/multiple-vulnerabilities-of-firewalls-AP-controllers-and-APs.shtml
seclists.org20220610 HNS-2022-02 - HN Security Advisory - Multiple vulnerabilities in Zyxel zyshhttp://seclists.org/fulldisclosure/2022/Jun/15mailing-list
packetstormsecurity.comhttp://packetstormsecurity.com/files/167464/Zyxel-Buffer-Overflow-Format-String-Command-Injection.html
packetstormsecurity.comhttp://packetstormsecurity.com/files/177036/Zyxel-zysh-Format-String-Proof-Of-Concept.html