CVE-2023-35136

mediumpriority · track · 0EPSS 0.002 · 15 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.24% (15th) EPSS

CVSS 5.5 · medium

Is it mine?

14 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

5.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.5mediumAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · FSTEC (BDU) RU

v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · ENISA EU

v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · security@zyxel.com.twexploitability 1.8 · impact 3.6

v3.15.1mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USCWE-20US

affected products (14)

Products and version ranges known to be affected.

Zyxel ATP series firmware≤ versions 4.32 through 5.37enisa_euvdEU
Zyxel USG FLEX 50(W) series firmware≤ versions 4.16 through 5.37enisa_euvdEU
Zyxel USG FLEX series firmware≤ versions 4.50 through 5.37enisa_euvdEU
Zyxel USG20(W)-VPN series firmware≤ versions 4.16 through 5.37enisa_euvdEU
Zyxel VPN series Firmware≤ versions 4.30 through 5.37enisa_euvdEU
Zyxel Communications Corp. ATP4.32 → 5.37fstec_bduRU
Zyxel Communications Corp. USG 20(W)-VPN4.16 → 5.37fstec_bduRU
Zyxel Communications Corp. USG FLEX4.50 → 5.37fstec_bduRU
Zyxel Communications Corp. USG FLEX 50(W)4.16 → 5.37fstec_bduRU
Zyxel Communications Corp. VPN4.30 → 5.37fstec_bduRU
zyxel zld4.16 → 5.37nvdUScpe:2.3:o:zyxel:zld:*:*:*:*:*:*:*:*
zyxel zld4.30 → 5.37nvdUScpe:2.3:o:zyxel:zld:*:*:*:*:*:*:*:*
zyxel zld4.32 → 5.37nvdUScpe:2.3:o:zyxel:zld:*:*:*:*:*:*:*:*
zyxel zld4.50 → 5.37nvdUScpe:2.3:o:zyxel:zld:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-3017Zyxel Firewall: Mehrere SchwachstellenDeutsch2023-11-27csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Zyxel Firewalls ausnutzen, um einen Cross-Site-Scripting-Angriff zu starten, einen Denial-of-Service-Zustand zu verursachen, vertrauliche Informationen offenzulegen oder Dateien zu manipulieren.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd cert_bund NVD CVE.org MITRE

published 2023-11-28modified 2026-06-17

references (4)

External citations — patches, advisories, analysis.

scry

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