CVE-2025-32463: Sudo Privilege Escalation Vulnerability

CVE-2025-32463 Overview

Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf from a user-controlled directory is used with the --chroot option.

Critical Impact

Local users can escalate privileges to root, compromising system integrity.

Affected Products

• sudo_project sudo
• canonical ubuntu_linux
• debian debian_linux

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to sudo_project
• Not Available - CVE CVE-2025-32463 assigned
• Not Available - sudo_project releases security patch
• 2025-06-30 - CVE CVE-2025-32463 published to NVD
• 2025-11-05 - Last updated in NVD database

Technical Details for CVE-2025-32463

Vulnerability Analysis

This vulnerability arises from the improper use of a user-controlled directory for the nsswitch.conf when using the --chroot option in sudo, allowing privilege escalation.

Root Cause

The root cause is the incorrect handling of nsswitch.conf paths during chroot operations, permitting user control.

Attack Vector

Local attack exploiting the --chroot option in sudo to escalate to root privileges.

# Example exploitation code (sanitized)
sudo --chroot /malicious_dir /etc/nsswitch.conf

Detection Methods for CVE-2025-32463

Indicators of Compromise

• Unusual entries in /var/log/sudo.log
• Unauthorized changes to /etc/nsswitch.conf
• Suspicious crontab entries

Detection Strategies

Employ monitoring tools that can detect unauthorized changes to /etc/nsswitch.conf, and audit logs for unusual sudo operations.

Monitoring Recommendations

Regularly check sudo logs and use file integrity monitoring solutions to track changes in sensitive directories.

How to Mitigate CVE-2025-32463

Immediate Actions Required

• Ensure /etc/nsswitch.conf is only writable by privileged users.
• Restrict sudo usage with the --chroot option to administrators only.
• Monitor and audit log files for any irregular sudo activities.

Patch Information

Apply updates provided in sudo's security advisories: https://www.sudo.ws/security/advisories/chroot_bug/

Workarounds

Temporarily disable the --chroot option in sudo configurations.

# Configuration example
echo 'Defaults !chroot' >> /etc/sudoers