CVE-2024-35314

Executive Summary

CVE-2024-35314 is a command injection vulnerability in Mitel MiCollab Desktop Client (up to version 9.7.1.110) and MiVoice Business Solution Virtual Instance (MiVB SVI) 1.0.0.25. An unauthenticated attacker can exploit insufficient parameter sanitization to execute arbitrary scripts, but successful exploitation requires user interaction. The vulnerability has a CVSS score of 0.0 (unscored) and no public proof-of-concept or patch is currently available. This report provides a comprehensive technical analysis, detection engineering rules, and mitigation strategies.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unscored)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: High (A:H)
• Threat Level: High (due to potential for arbitrary code execution)

Deep Dive & Mechanics

The vulnerability resides in the Desktop Client of Mitel MiCollab and the MiVB SVI. The application fails to properly sanitize user-supplied input before passing it to a command execution function. An attacker can craft a malicious request that, when processed by the client (requiring user interaction such as clicking a link or opening a file), injects arbitrary operating system commands. The injected commands run with the privileges of the affected application, potentially leading to full system compromise.

The core issue is a classic command injection (CWE-77) where special characters like ;, |, &, or backticks are not filtered. For example, a parameter like hostname might be concatenated directly into a shell command without escaping.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

import subprocess
def connect_to_server(hostname):
    command = "ping -c 1 " + hostname
    subprocess.call(command, shell=True)

Patched Code (Conceptual):

import subprocess
import shlex
def connect_to_server(hostname):
    safe_hostname = shlex.quote(hostname)
    command = "ping -c 1 " + safe_hostname
    subprocess.call(command, shell=True)

The patched version uses shlex.quote() to escape shell metacharacters, preventing injection.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Install Mitel MiCollab Desktop Client 9.7.1.110 on a Windows VM.
2. Set up a listener on attacker machine (e.g., nc -lvnp 4444).
3. Craft a malicious payload in a parameter (e.g., hostname).

Exploit Payload (Conceptual):

http://target/micollab?hostname=127.0.0.1;calc.exe

Usage:

• Send the crafted link to the victim via email or social engineering.
• When the victim clicks the link, the command calc.exe executes.

Note: No public exploit code is available; this is a conceptual demonstration.

Blue Team

Detection:

• Monitor for unusual child processes spawned by the MiCollab client (e.g., cmd.exe, powershell.exe).
• Look for network connections to unexpected IPs after user interaction.
• Enable application whitelisting to block unauthorized executables.

Hunting:

• Search logs for parameters containing shell metacharacters (;, |, &, `).
• Use Sysmon Event ID 1 (Process Creation) to detect anomalous command lines.

Indicators of Compromise (IOCs)

• Network: Outbound connections to attacker-controlled IPs on common ports (80, 443, 4444).
• Process: Spawning of cmd.exe, powershell.exe, or wscript.exe from MiCollab client.
• File: Creation of suspicious files in %TEMP% or %APPDATA% directories.
• Registry: Unauthorized modifications to HKCU\Software\Microsoft\Windows\CurrentVersion\Run.

Detection Engineering

YARA Rule

rule CVE_2024_35314_Mitel_MiCollab_Command_Injection {
    meta:
        description = "Detects command injection attempts in Mitel MiCollab logs"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-35314"
    strings:
        $cmd1 = /[;&|`$]/ nocase
        $cmd2 = /(cmd|powershell|wscript|cscript)/ nocase
    condition:
        any of ($cmd*) and filesize < 10MB
}

Sigma Rule

title: Mitel MiCollab Command Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects command injection attempts in Mitel MiCollab logs
author: Valters IT
date: 2024-01-01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-35314
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
            - '\wscript.exe'
        ParentImage|endswith: '\MiCollab.exe'
    condition: selection
falsepositives:
    - Legitimate administrative tasks
level: high

Suricata Rule

alert tcp any any -> any any (msg:"CVE-2024-35314 Mitel MiCollab Command Injection Attempt"; flow:to_server,established; content:"hostname="; nocase; pcre:"/hostname=[^&]*[;&|`]/"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:

   • Disable the Desktop Client if not essential.
   • Restrict network access to the MiCollab server.
   • Implement strict input validation and output encoding.

2. Long-term Fix:

   • Apply vendor patch when available.
   • Upgrade to a patched version of MiCollab (check vendor advisory).
   • Use parameterized commands or safe APIs (e.g., subprocess.run with shell=False).

3. Compensating Controls:

   • Deploy Web Application Firewall (WAF) rules to block injection patterns.
   • Enable application control to prevent unauthorized executables.
   • Conduct regular security audits and penetration testing.

Valters IT Signature
This report is provided for authorized security testing and defensive purposes only. Unauthorized use is prohibited.