🛡️ CVE-2023-35138 — nas326-firmware

🔴 CVSS 9.8 — Critical ✅ No Known Exploit CWE-78 NVD
9.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A command injection vulnerability in the “show_zysync_server_contents” function of the Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted HTTP POST request.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2023-35138 is classified as CWE-78: OS Command Injection. Untrusted input reaches a shell command without neutralisation, so an attacker can run arbitrary operating system commands.

Affected software

CVE-2023-35138 is recorded against 2 packages.

  • nas326-firmware (fixed in 5.21\(aazf.14\)c0)
  • nas542-firmware (fixed in 5.21\(abag.11\)c0)

Timeline and source

Published on 30 November 2023 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

www.zyxel.com
www.zyxel.com

Details

Severity CRITICAL
CVSS Score 9.8
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE CWE-78
Public Exploit ✅ No
Source NVD
Published 2023-11-30
Updated 2026-08-11
Modified 2026-06-17

Affected Packages

Software From version Fixed in
nas326-firmware — 5.21\(aazf.14\)c0
nas542-firmware — 5.21\(abag.11\)c0

Similar Threats

Exploit Protection

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CVE-2023-35138 carries CVSS 9.8 Critical rating. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

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