CVE-2024-33618

Executive Summary

CVE-2024-33618 is an uncontrolled resource consumption vulnerability in Bosch VMS Central Server, specifically in version 12.0.1. The flaw allows an unauthenticated attacker to exhaust disk space on the server by sending specially crafted network traffic. This leads to a denial-of-service (DoS) condition, potentially disrupting video management operations. No public exploit code or patch details are currently available, but the vulnerability is rated high severity (CVSS 7.5) due to its low attack complexity and network-based vector.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
• Base Score: 7.5 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: None (I:N)
• Availability Impact: High (A:H)

The threat level is high due to the ease of exploitation and the potential for complete service disruption. The EPSS score of 0.0% suggests low current exploitation activity, but this may change as details emerge.

Deep Dive & Mechanics

The vulnerability resides in the Bosch VMS Central Server's network interface handling. The server fails to properly limit the amount of data it accepts or processes from network connections. An attacker can send a continuous stream of data (e.g., large packets, repeated requests, or malformed data) that the server stores or processes without bounds, eventually filling the disk partition. This uncontrolled resource consumption (CWE-400) leads to a denial-of-service condition where the server can no longer write logs, store video, or perform essential functions.

The attack does not require authentication or user interaction, making it particularly dangerous for exposed systems. The exact mechanism likely involves a buffer or temporary file that grows indefinitely, or a logging function that writes excessive data to disk.

Vulnerable vs. Patched Code

No patched version or code diff is available. The vulnerable version is Bosch VMS 12.0.1. The fix would likely involve implementing rate limiting, input validation, or disk quota checks on network data processing. Without a patch, the only mitigation is network-level controls.

Exploitation & Lab Setup

Red Team

Lab Setup:

• Target: Bosch VMS Central Server 12.0.1 (IP: 192.168.1.100)
• Attacker: Kali Linux (IP: 192.168.1.50)
• Network: Isolated lab with no production impact

Exploitation Steps:

1. Identify the target service (likely port 443 or a custom port).
2. Use a tool like hping3 or a custom Python script to send a flood of data to the server's network interface.
3. Monitor disk usage on the target to confirm exhaustion.

Example Python script (conceptual):

import socket
import time

target_ip = "192.168.1.100"
target_port = 443

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((target_ip, target_port))

# Send large payload repeatedly
payload = b"A" * 65535
while True:
    sock.send(payload)
    time.sleep(0.01)

Note: This is a proof-of-concept. Actual exploitation may require specific protocol details.

Blue Team

Detection & Response:

• Monitor disk usage alerts on VMS servers.
• Set up network traffic baselines and alert on unusual data volumes.
• Implement rate limiting on network interfaces.
• Use intrusion detection systems (IDS) to detect abnormal traffic patterns.

Hunting Queries:

• Search for logs showing rapid disk space consumption.
• Look for sustained high network traffic to the VMS server from a single source.

Indicators of Compromise (IOCs)

• Network: Unusually high volume of TCP traffic to the VMS server (e.g., >100 Mbps sustained).
• System: Rapid disk space depletion on the VMS server partition.
• Logs: Repeated connection attempts or large data receipts in server logs.
• File System: Unexpected large temporary files or log files in the VMS data directory.

Detection Engineering

YARA Rule

rule CVE_2024_33618_Bosch_VMS_Disk_Exhaustion {
    meta:
        description = "Detects disk exhaustion patterns from CVE-2024-33618"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-33618"
    strings:
        $disk_full = "No space left on device" nocase
        $vms_log = "VMS Central Server" nocase
    condition:
        $disk_full and $vms_log
}

Sigma Rule

title: Bosch VMS Disk Exhaustion Detection
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects disk space exhaustion events on Bosch VMS servers
logsource:
    product: windows
    service: system
detection:
    selection:
        EventID: 2020
        Provider_Name: "NTFS"
        Message: "No space left on device"
    condition: selection
falsepositives:
    - Legitimate disk full scenarios
level: high

Suricata Rule

alert tcp any any -> $HOME_NET 443 (msg:"CVE-2024-33618 Bosch VMS Disk Exhaustion Attempt"; flow:to_server; content:"|41 41 41|"; depth:3; threshold: type both, track by_src, count 1000, seconds 60; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Mitigations:

• Restrict network access to the VMS Central Server using firewall rules (allow only trusted IPs).
• Implement network rate limiting or traffic shaping on the VMS server's interface.
• Monitor disk usage and set up alerts for rapid consumption.
• If possible, apply vendor patches when released.

Long-Term Fix:

• Apply the official patch from Bosch when available.
• Upgrade to a patched version of Bosch VMS.
• Conduct a security review of network-facing services.

Workarounds:

• Use a reverse proxy or load balancer to filter traffic.
• Enable disk quotas on the VMS server partition.

Valters IT

{/* [Security Hash: 9A363792022ABCD64A955A1B] */}