CVE-2023-35136 | BDVDB-2026-217849 Detail

ZyxelATP series firmware

Description#

An improper input validation vulnerability in the “Quagga” package of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an authenticated local attacker to access configuration files on an affected device.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact none, availability impact none. Attack vector: local.

Weaknesses#

CWE-20 Improper Input Validation

References#

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps

Exploit#

No public exploit known

History#

Version 12023-11-28Record published in the CVE List.
Version 22025-06-05Most recent update recorded in the CVE List.

Published

Published: 2023-11-28
Last modified: 2025-06-05

Vendor information

Vendor: Zyxel
Product: ATP series firmware

All Zyxel vulnerabilities

Score

5.5 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 15.6.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Improper Input Validation

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
versions 4.32 through 5.37
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

5.5 Medium

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

Metric breakdown
Attack Vector	Local
Attack Complexity	Low
Privileges Required	Low
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	None
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).