CVE intelligence and bounded remediation

CVE-2023-22914 — Zyxel Usg Flex 100 Firmware security vulnerability

High CVSS 7.2

A path traversal vulnerability in the “account_print.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker with administrator privileges to execute unauthorized OS commands in the “tmp” directory by uploading a crafted file if the hotspot function were enabled.

Severity
High
CVSS
7.2 (3.1)
Published
2023-04-24
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-22

Affected products

  • zyxel / usg_flex_100_firmware
  • zyxel / usg_flex_100w_firmware
  • zyxel / usg_flex_200_firmware
  • zyxel / usg_flex_50_firmware
  • zyxel / usg_flex_50w_firmware
  • zyxel / usg_flex_500_firmware

Showing 6 representative product identities from 11 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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