# CVE-2026-77683: Comfast CF-N1-S command injection in NTP timezone

Source: https://junglewise.ai/threats/cve-2026-77683-comfast-cf-n1-s-command-injection-in-ntp-timezone  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-21. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77683 · Severity: critical · CVSS 9.9 · Published 2026-08-21

The Comfast CF-N1-S router's web management interface contains a command injection vulnerability in the NTP timezone configuration endpoint. An authenticated attacker can send a specially crafted request to execute arbitrary commands on the router with full system privileges, potentially allowing complete device compromise, data theft, or use as a pivot point for network attacks.

Technologies: [Comfast CF-N1-S](https://junglewise.ai/threats/technologies/cf-n1-s). Vendors: [Comfast](https://junglewise.ai/threats/vendors/comfast).

## Quick answers

**Is CVE-2026-77683 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77683 being exploited in the wild.

**How severe is CVE-2026-77683?** Critical severity, with a CVSS score of 9.9, published 21 August 2026.

**Which products and versions are affected?** Comfast CF-N1-S 2.6.0.1.

**Is there a fix for CVE-2026-77683?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-77683 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-77683?** Check whether you run Comfast CF-N1-S 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

A command injection vulnerability exists in the /cgi-bin/mbox-config endpoint (method=SET&section=ntp_timezone) of the webmgnt component, specifically in function sub_41AD7C. The user-supplied timestr parameter is passed unsanitized through sprintf() into a system() call, allowing OS command injection. The vulnerability requires two conditions: the timestr field must be non-empty and ntp_client_enabled must equal "0". While the vulnerability requires an authenticated session, exploitation is straightforward via HTTP POST and results in unauthenticated remote code execution from the attacker's perspective once a session is established. Public exploit code is available.

## Affected products

- Comfast CF-N1-S 2.6.0.1

## Timeline

- 2026-07-06: disclosed: Vulnerability reported on GitHub
- 2026-08-21: advisory: CVE-2026-77683 published on NVD

## References

- [https://github.com/AdminSafe/CVE/issues/8](https://github.com/AdminSafe/CVE/issues/8)
- [https://vuldb.com/cve/CVE-2026-77683](https://vuldb.com/cve/CVE-2026-77683)

## Related threats

- [Comfast CF-N1-S stack-based buffer overflow in web management](https://junglewise.ai/threats/cve-2026-94003-a-vulnerability-has-been-found-in-comfast-cf-n1-s-2-6-0-1)
- [Comfast CF-N1-S command injection in webmgnt](https://junglewise.ai/threats/cve-2026-75364-comfast-cf-n1-s-command-injection-in-webmgnt)
- [Comfast CF-N1-S stack buffer overflow in NTP timezone configuration](https://junglewise.ai/threats/cve-2026-78050-comfast-cf-n1-s-stack-buffer-overflow-in-ntp-timezone)
- [Comfast CF-N1-S stack-based buffer overflow in web management](https://junglewise.ai/threats/cve-2026-77148-comfast-cf-n1-s-stack-based-buffer-overflow-in-web-management)
- [Comfast CF-N1-S stack-based buffer overflow in SSID configuration](https://junglewise.ai/threats/cve-2026-77022-comfast-cf-n1-s-stack-based-buffer-overflow-in-ssid-configuration)