dbcve.org
ZldOperating system · Zyxel

CVE-2024-7203

HIGH · 7.2 CVSS v3.1 Published 2024-09-03
Fix available
A fix is available. Upgrade to 5.39 or later.
See remediation →
78/100
Remediation priority · High
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.60 through V5.38 and USG FLEX series firmware versions from V4.60 through V5.38 could allow an authenticated attacker with administrator privileges to execute some operating system (OS) commands on an affected device by executing a crafted CLI command.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a post-authentication command injection vulnerability in Zyxel ATP and USG FLEX series firewalls. An attacker with administrator-level credentials can execute arbitrary OS commands by sending crafted CLI commands to the affected device, due to insufficient input validation in the command-line interface.

MitigationUpdate firmware to a version beyond V5.38 and restrict administrative access to trusted personnel only.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ZldOperating system
Affected:>= 4.60, < 5.39

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Access the device web interface or CLI and verify the model is a Zyxel ATP or USG FLEX series firewall
    Affected if Device is not an ATP or USG FLEX model - the vulnerability does not apply
  2. Check firmware version
    In the web interface, go to Maintenance > Firmware or use CLI command 'show version' to determine the Zld firmware version
    Affected if Firmware version is Zld >= 4.60 and < 5.39 - this version range is affected by the vulnerability
  3. Verify administrative access is enabled
    Check device configuration for enabled administrative access methods: go to Configuration > Object > Service > Service Group or use CLI 'show admin' to see admin accounts and access settings
    Affected if Administrative access is enabled and admin credentials exist - the vulnerability requires valid admin credentials to exploit
  4. Check remote admin access exposure
    Review firewall rules or NAT settings in Configuration > Security Policy > Policy Control to determine if the management interface (HTTP/HTTPS/SSH/Telnet) is exposed to untrusted networks
    Affected if Administrative interfaces are reachable from untrusted networks - this increases exposure to attackers with stolen admin credentials

The environment is affected if the device is an ATP or USG FLEX model running Zld firmware version 4.60 through 5.38 and administrative access is configured, regardless of network exposure since valid admin credentials are required for exploitation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.39 or later
Fixed in 5.39
Interim mitigation

Update firmware to a version beyond V5.38 and restrict administrative access to trusted personnel only.

Recommended fix High confidence

Zyxel ATP and USG FLEX firmware version 5.39 or later

  1. 1. Log into the Zyxel ATP or USG FLEX device administration interface
  2. 2. Navigate to the firmware upgrade section (typically under Maintenance > Firmware Upgrade)
  3. 3. Download the latest firmware version 5.39 or later from the official Zyxel support website (www.zyxel.com)
  4. 4. Upload the firmware file to the device and initiate the upgrade process
  5. 5. Wait for the device to reboot and complete the firmware installation
  6. 6. Verify the firmware version after reboot to confirm the upgrade was successful
Caveat Standard firmware upgrade - ensure to backup configuration before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Zld Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-7203 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-7203 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data