CVE-2025-15137 — Critical Command Injection Vulnerability in TRENDnet TEW-800MB

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CVE Identifier: CVE-2025-15137
Published: December 28, 2025
Severity: High (CVSS ~8.8 / 9.0, depending on source)
Exploit Status: Proof-of-Concept (PoC) / exploit publicly available
Vendor Response: No known official patch or vendor response at time of publication

What Is This Vulnerability?

CVE-2025-15137 is a remote command injection flaw discovered in TRENDnet TEW-800MB (firmware version 1.0.1.0), an older network router/access point model.

The flaw is located in the CGI executable file NTPSyncWithHost.cgi, specifically within a function identified as sub_F934. Improper input validation in this function allows an attacker to inject arbitrary system commands — which the device will execute — when handling NTP sync requests.

Because the vulnerable code fails to sanitize user-controlled input before using it in system commands, attackers who can reach this CGI endpoint may leverage it to execute arbitrary OS commands.

Why It Matters — Impact & Severity

This vulnerability is rated high severity on common scoring systems:

CVSS Breakdown (Approximate)

  • Attack Vector: Network (remote exploitation)
  • Attack Complexity: Low
  • Privileges Required: Low
  • User Interaction: None
  • Confidentiality Impact: High
  • Integrity Impact: High
  • Availability Impact: High
  • Typical Score: ~8.8 / 9.0 (High)

These metrics mean:

  1. An attacker does not need physical access
  2. Exploitation is simple and reproducible
  3. A compromised device could leak sensitive data, be altered, or be taken offline
  4. The publicly available exploit increases the likelihood of real-world attacks

Command Injection — How It Works

Command injection weaknesses occur when untrusted inputs (such as URL parameters or form fields) are passed directly into system-level commands without proper sanitization.

In this case, the vulnerable NTP sync handler constructs a command using parameters from an HTTP request. Because the input isn’t safely filtered (and escapes or special characters aren’t neutralized), an attacker can append malicious instructions that are executed by the device’s underlying operating system.

This type of vulnerability is classified under:

  • CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component
  • CWE-77: Improper Neutralization of Special Elements Used in a Command (Command Injection)

Exploit & Threat Landscape

  • Exploit code is publicly available, meaning that attackers can test and weaponize this vulnerability without deep reverse-engineering knowledge.
  • Many automated scanning tools already flag this CVE, increasing risk.
  • Vendors have not yet issued official patches, and TRENDnet has reportedly not responded to early contact attempts about the issue.

Command injection bugs are often used in:

  1. Remote compromise of devices
  2. Lateral movement within networks
  3. Deployment of malware / botnets
  4. Persistent backdoors

Who Is Affected?

Affected Device:

  • TRENDnet TEW-800MB
  • Firmware: 1.0.1.0 (the only confirmed vulnerable version)

Note: If you are operating this model or see it in your environment, treat it as at-risk until mitigated.

Mitigation & Best Practices

Until an official patch is released:

Mitigation Steps

  1. Disable remote management (if enabled) to limit exposure.
  2. Isolate the device behind a firewall (block HTTP/HTTPS access from untrusted networks).
  3. Monitor for unusual activity (new connections, unexpected NTP queries).
  4. Remove old or unused devices — consider replacing end-of-life hardware.
  5. Check TRENDnet advisories for firmware updates that may be released.

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