Junglewise Threat Intelligence

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

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

Executive brief

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.

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

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