CVE-2026-26225: Intego Personal Backup Privilege Escalation

CVE-2026-26225 Overview

Intego Personal Backup, a macOS backup utility that allows users to create scheduled backups and bootable system clones, contains a local privilege escalation vulnerability. Backup task definitions are stored in a location writable by non-privileged users while being processed with elevated privileges. By crafting a malicious serialized task file, a local attacker can trigger arbitrary file writes to sensitive system locations, leading to privilege escalation to root.

Critical Impact

Local attackers can exploit insecure task file handling to achieve arbitrary file writes and escalate privileges to root on affected macOS systems.

Affected Products

• Intego Personal Backup X9 (macOS)
• Intego Personal Backup (versions prior to patched release)
• macOS systems running vulnerable Intego Personal Backup installations

Discovery Timeline

• 2026-02-12 - CVE-2026-26225 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2026-26225

Vulnerability Analysis

This vulnerability (CWE-59: Improper Link Resolution Before File Access) exists in Intego Personal Backup's handling of backup task definition files. The application stores task configuration files in a directory that is writable by standard non-privileged users on macOS. When the backup service processes these task files, it does so with elevated (root) privileges without properly validating the integrity or origin of the task definitions.

The core issue stems from a trust boundary violation where user-controlled data influences privileged operations. When the backup daemon parses serialized task files, an attacker can craft malicious task definitions that specify arbitrary file paths as backup destinations. This enables arbitrary file write operations to protected system locations, such as /Library/LaunchDaemons/ or /etc/, which normally require root access.

Root Cause

The root cause is an insecure file permission model combined with improper handling of symbolic links and file paths in the task definition parser. The backup service fails to:

1. Validate that task files originate from trusted sources before processing them with elevated privileges
2. Properly resolve and sanitize file paths specified in backup task configurations
3. Implement appropriate access controls on the task definition storage directory
4. Follow secure coding practices for operations involving privilege boundaries

This creates a classic symlink attack (CWE-59) scenario where user-controlled symbolic links can redirect privileged file operations to unintended locations.

Attack Vector

The attack requires local access to the target macOS system. An attacker with standard user privileges can exploit this vulnerability through the following general approach:

1. Identify the writable task file storage location used by Intego Personal Backup
2. Craft a malicious serialized task definition that specifies sensitive system paths as backup destinations
3. Place the malicious task file in the monitored directory or modify existing task files
4. Wait for the privileged backup service to process the malicious task definition
5. The service executes arbitrary file writes with root privileges, enabling persistence mechanisms or further privilege escalation

The attack does not require user interaction beyond the initial local access, and exploitation complexity is considered low due to the straightforward nature of crafting malicious task files. For detailed technical analysis, refer to the QuarksLab Blog Analysis.

Detection Methods for CVE-2026-26225

Indicators of Compromise

• Unexpected modifications to Intego Personal Backup task definition files
• Suspicious symbolic links created within the backup task storage directories
• Unauthorized file writes to protected system locations such as /Library/LaunchDaemons/ or /etc/
• New persistence mechanisms (LaunchDaemons, LaunchAgents) appearing without administrator action

Detection Strategies

• Monitor file system activity in Intego Personal Backup's task configuration directories for unauthorized modifications
• Implement file integrity monitoring on the backup application's configuration storage paths
• Watch for privilege escalation attempts following file write operations to system directories
• Deploy endpoint detection rules to alert on symbolic link creation in backup-related directories

Monitoring Recommendations

• Enable macOS unified logging and audit trail for file system operations in sensitive directories
• Configure SentinelOne Singularity to detect suspicious privilege escalation patterns on macOS endpoints
• Implement real-time monitoring for new LaunchDaemon or LaunchAgent installations
• Audit process behavior for the Intego Personal Backup daemon to identify anomalous file operations

How to Mitigate CVE-2026-26225

Immediate Actions Required

• Check for and apply the latest Intego Personal Backup updates from the Intego Release Notes
• Restrict access to the backup task definition directories to administrative users only
• Review existing backup task files for any unauthorized modifications or suspicious content
• Monitor systems for indicators of exploitation until patches are applied

Patch Information

Organizations should consult the official Intego Personal Backup X9 Release Notes for the latest security updates addressing this vulnerability. Apply all available patches immediately. Additional vulnerability details are available from the VulnCheck Advisory.

Workarounds

• Temporarily restrict write permissions on the task definition storage directories to prevent unauthorized task file creation
• Consider disabling the Intego Personal Backup service on high-value systems until patches are applied
• Implement additional access controls using macOS security features such as System Integrity Protection (SIP) extensions
• Use alternative backup solutions that do not exhibit this vulnerability pattern until remediation is complete

# Configuration example - Restrict task directory permissions (adjust path as needed)
# Identify the task file storage location first
sudo chmod 700 /path/to/intego/task/directory
sudo chown root:wheel /path/to/intego/task/directory
# Monitor for unauthorized access attempts
log stream --predicate 'process == "IntegoDaemon"' --info