CVE-2025-32463 - Sudo Chroot Privilege Escalation

This tutorial provides a comprehensive guide to understanding CVE-2025-32463, a local privilege escalation vulnerability in the sudo binary.

• CVE ID: CVE-2025-32463
• Type: Local Privilege Escalation (LPE)
• Component: sudo binary (1.9.14 to 1.9.17)
• Attack Vector: Local
• Authentication: Low privileges required

Understanding the Vulnerability

CVE-2025-32463 is a privilege escalation vulnerability in the sudo chroot functionality. The vulnerability allows a local user with limited sudo privileges to escalate to root access through manipulation of the chroot environment.

The vulnerability comes from insuficient validation in sudo's chroot implementation, specifically in how it handles:

• Path traversal in chroot directories
• File system boundary checks
• Permission validation during chroot operations

Required Tools & Environment

• Linux system with vulnerable sudo version
• Terminal access
• Git (for cloning repositories)

Proof of Concept (PoC)

Step 1: Verify Sudo Version

# Check sudo version
sudo --version

Look for vulnerable versions: 1.9.14 to 1.9.17

Step 2: Download The PoC Exploit

# Clone the exploit's repository
git clone https://github.com/kh4sh3i/CVE-2025-32463.git
cd CVE-2025-32463
 
# Make exploit script executable
chmod +x exploit.sh

Step 3: Exploit!

# See what user you're currently using
id
 
# Run the Exploit
./exploit.sh
 
# Now, you will see yourself as root
id

Mitigation Strategies

Immediate Actions

1. Update sudo

   # Update to patched version
   sudo apt update && sudo apt upgrade sudo
    
   # Verify version
   sudo --version

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2. Review sudo Configuration

   # Audit sudoers file
   sudo visudo -c
    
   # Remove unnecessary chroot permissions
   sudo visudo

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Long-term Security Measures

1. Implement Least Privilege

   • Grant minimal necessary sudo permissions
   • Regular audit of sudo configurations
   • Use role-based access control

2. Security Frameworks

   # Enable AppArmor
   sudo systemctl enable apparmor
   sudo systemctl start apparmor
    
   # Configure SELinux (if using Red Hat-based systems)
   sudo setsebool -P allow_execstack off

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3. Monitoring and Logging

   # Enhanced sudo logging
   echo "Defaults log_host, log_year, logfile=/var/log/sudo.log" >> /etc/sudoers
    
   # Set up log rotation
   sudo logrotate -f /etc/logrotate.d/sudo

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Conclusion

CVE-2025-32463 demonstrates the importance of proper input validation and security boundaries in privileged system utilities. Key takeaways:

For System Administrators

• Regularly update system components
• Implement defense-in-depth strategies
• Monitor for unusual privilege escalation attempts
• Maintain minimal sudo privileges

For Security Researchers

• Understand the vulnerability mechanics
• Develop proper detection methods
• Contribute to security community knowledge
• Practice responsible disclosure

Resources and References

• CVE-2025-32463 on NVD
• Rich Mirch's Twitter