CVE-2023-35136

MEDIUM

5.5

CVSS Score

Published: November 28, 2023 at 01:16 AM UTC

Updated: June 17, 2026 at 06:04 AM UTC

25 products affected across 1 vendorZldUsg Flex 200Usg Flex 500

Using ATP series firmware by Zyxel?

Get instant alerts when new vulnerabilities affect ATP series firmware - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Zld · Zyxel

95%

4.16 ≤ v ≤ 5.374.30 ≤ v ≤ 5.374.32 ≤ v ≤ 5.374.50 ≤ v ≤ 5.37

zyxel-atp100 (environment) · zyxel-atp100w (environment) · zyxel-atp200 (environment) · zyxel-atp500 (environment) · zyxel-atp700 (environment) · zyxel-atp800 (environment) · zyxel-usg-20w-vpn (environment) · zyxel-usg-flex-100 (environment) · zyxel-usg-flex-100w (environment) · zyxel-usg-flex-200 (environment) · zyxel-usg-flex-50 (environment) · zyxel-usg-flex-500 (environment) · zyxel-usg-flex-50w (environment) · zyxel-usg-flex-700 (environment) · zyxel-vpn100 (environment) · zyxel-vpn1000 (environment) · zyxel-vpn300 (environment) · zyxel-vpn50 (environment) · zyxel-vpn50w (environment)

ATP · Zyxel

60%

v ≤ 5.37

USG FLEX · Zyxel

60%

v ≤ 5.37

Usg Flex 50 · Zyxel

60%

v ≤ 5.37

Usg Flex 50W · Zyxel

60%

v ≤ 5.37