External risk intelligence

Comfast CF-N1-S URI Parameter Parsing Stack Buffer Overflow

CVE advisorySeverity: CRITICAL (CVSS 10.0)

CVE-2026-76008

The vulnerability exists in a CGI-based configuration interface of a networking device. Such management interfaces are commonly exposed to the network or internet to allow administrative access, and the flaw is remotely reachable through standard URI parameter manipulation.

Memory Corruption

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in a network device's configuration function that could allow remote attackers to execute arbitrary code by manipulating input parameters. This flaw, a stack-based buffer overflow, impacts the URI parameter parsing component.

  • Flaw allows remote attackers to execute code.
  • Critical flaw in network device configuration function.
  • Confirm relevance and exposure of affected devices.

Attack Path

How an attacker could exploit the issue

An attacker can remotely target a networking device by sending specially crafted requests to its configuration interface. This allows them to manipulate parameters within the URI, leading to a stack-based buffer overflow in the URI Parameter Parsing component. If successful, this could result in a compromise of the device.

  • Remotely accessible configuration interface.
  • Manipulating URI parameters triggers overflow.
  • Potential for full device compromise.

Live Threat

Current exploitation, exposure, and threat context

A remote attacker could exploit a stack-based buffer overflow vulnerability in the URI parameter parsing component of Comfast CF-N1-S. This could lead to a compromise of the device's integrity and availability.

  • System configuration data at risk.
  • Remote network access enables manipulation.
  • Device availability and integrity may be affected.

Operational Fix

Recommended remediation, mitigation, and detection steps

The real-world response to this vulnerability likely involves networking and security teams, as it affects a device with a network-exposed configuration interface. The first critical step is to identify all instances of the affected technology within the environment, determine their accessibility and business criticality, and then locate the system owners responsible for remediation. A risk-based approach should guide the subsequent planning and execution of fixes or mitigation strategies.

  • Identify network device owners for accountability.
  • Verify external reachability and business impact.
  • Coordinate vendor engagement for remediation.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is the Comfast CF-N1-S?

The Comfast CF-N1-S is a networking device that provides connectivity features. It utilizes a web-based management interface, specifically including a CGI-based component for handling configuration settings via URI parameters.

What does CVE-2026-76008 mean for this device?

This vulnerability is a stack-based buffer overflow, classified under CWE-121. It occurs when the device's URI parsing component fails to safely handle input for specific parameters, potentially allowing an attacker to overwrite memory and execute arbitrary code.

How is this stack-based buffer overflow triggered?

The flaw is triggered by sending a specially crafted web request to the /cgi-bin/mbox-config interface. By providing unexpected or excessive data within the width or height parameters, an attacker can crash the parsing process or take control. Normal, valid configuration requests do not trigger this memory error.

Why does Halo Surface Signal categorize this as an external risk?

Halo Surface Signal flags this as external because the vulnerability exists in a configuration interface. Since these management portals are often accessible over a network or the internet to facilitate remote administration, they are frequently reachable by unauthorized parties.

What should I do if I use Comfast CF-N1-S devices?

Start by locating all units within your environment and assessing their network reachability. Prioritize isolating devices that are accessible from the internet. Coordinate with your system owners to review device placement and verify if vendor updates are available to address the flawed parsing logic.

References