Home/CVE/A command injection vulnerability in the Free Time WiFi hotspot feature of the Zyxel USG FLEX series firmware versions 4
CVE

CVE-2023-34139

A command injection vulnerability in the Free Time WiFi hotspot feature of the Zyxel USG FLEX series firmware versions 4

A command injection vulnerability in the Free Time WiFi hotspot feature of the Zyxel USG FLEX series firmware versions 4.50 through 5.36 Patch 2 and VPN series firmware versions 4.20 through 5.36 Patch 2, could allow an unauthenticated, LAN-based attacker to execute some OS commands on an affected device.

HIGH · CVSS 8.8 EPSS 0.00186
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
▤

Affected Products & Versions

15
zyxel usg 2200-vpn firmware>= 4.20 and < 5.37
zyxel usg flex 100 firmware>= 4.50 and < 5.37
zyxel usg flex 100w firmware>= 4.50 and < 5.37
zyxel usg flex 200 firmware>= 4.50 and < 5.37
zyxel usg flex 50 firmware>= 4.50 and < 5.37
zyxel usg flex 500 firmware>= 4.50 and < 5.37
zyxel usg flex 50w firmware>= 4.50 and < 5.37
zyxel usg flex 700 firmware>= 4.50 and < 5.37
▣

Scoring & Timeline

8.8
HIGH · CVSS v3.1 · security@zyxel.com.tw
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD17 Jul 2023 · 06:15 PM
CVSS VectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-wlan-controllersVendor Advisory
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