# CVE-2025-4106: WatchGuard Firebox leftover debug code in diagnostic shell

Source: https://junglewise.ai/threats/cve-2025-4106-watchguard-firebox-leftover-debug-code-in-diagnostic-shell  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-10-24. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2025-4106 · Severity: info · CVSS 8.9 · Published 2025-10-24

WatchGuard Firebox is a network firewall that protects corporate infrastructure. An authenticated administrator with both web and command-line access can exploit leftover diagnostic code to enable a debug shell, potentially gaining deep system access and the ability to modify firewall behavior or access sensitive configuration data.

Technologies: [Watchguard Firebox](https://junglewise.ai/threats/technologies/firebox). Vendors: [Watchguard](https://junglewise.ai/threats/vendors/watchguard).

## Quick answers

**Is CVE-2025-4106 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-4106 being exploited in the wild.

**How severe is CVE-2025-4106?** Informational severity, with a CVSS score of 8.9, published 24 October 2025.

**Which products and versions are affected?** Watchguard Firebox Fireware OS 12.0 - 12.11.2 (Default); Fireware OS 12.0 - 12.5.12 (T15/T35).

**Is there a fix for CVE-2025-4106?** A patch was published on 2025-10-24: Fireware OS 12.11.3 and 12.5.13 available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-4106 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2025-4106?** Check whether you run Watchguard Firebox at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This vulnerability involves leftover debug code (CWE-489) in WatchGuard Firebox that allows an authenticated admin user to enable a diagnostic debug shell. The attack requires the attacker to have admin credentials and access to both the management WebUI and command-line interface, and involves uploading a platform and version-specific diagnostic package followed by executing a debug command. An attacker exploiting this can gain shell access to the firewall system with admin privileges. Patches are available: Fireware OS 12.11.3 for Default platforms and 12.5.13 for T15/T35 platforms.

## Affected products

- WatchGuard Firebox Fireware OS 12.0 - 12.11.2 (Default); Fireware OS 12.0 - 12.5.12 (T15/T35)

## Timeline

- 2025-10-24: disclosed
- 2025-10-24: patched: Fireware OS 12.11.3 and 12.5.13 available

## References

- [https://psirt.watchguard.com/CVE-2025-4106](https://psirt.watchguard.com/CVE-2025-4106)
- [https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00010](https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00010)

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