CVE-2024-42028: UniFi Network Server Privilege Escalation

CVE-2024-42028 Overview

A Local privilege escalation vulnerability found in a Self-Hosted UniFi Network Server with UniFi Network Application (Version 8.4.62 and earlier) allows a malicious actor with a local operational system user to execute high privilege actions on UniFi Network Server.

Critical Impact

This vulnerability could allow attackers with local access to escalate privileges, potentially compromising sensitive data or altering system configurations.

Affected Products

• UniFi Network Application (Version 8.4.62 and earlier)

Discovery Timeline

• 2024-10-28 - CVE-2024-42028 published to NVD
• 2024-10-29 - Last updated in NVD database

Technical Details for CVE-2024-42028

Vulnerability Analysis

This is a privilege escalation vulnerability due to improper access control (CWE-276). The application fails to enforce necessary security constraints, allowing local users to gain higher privileges.

Root Cause

The issue arises from incorrect permission handling in system libraries used by the UniFi Network Application, which fails to properly restrict access to system commands.

Attack Vector

Local

# Example exploitation code (sanitized)
sudo sysctl -w kernel.sysrq=1

# Manipulate restricted files
echo "1" > /proc/sys/kernel/sysrq

Detection Methods for CVE-2024-42028

Indicators of Compromise

• Unexpected entries in /var/log/auth.log
• Unauthorized modifications to system files
• Unusual spikes in user privilege levels

Detection Strategies

Monitor for changes in file permissions and any unsanctioned use of administrative commands, particularly those involving system configurations.

Monitoring Recommendations

Set up alerts for modifications in the sudoers file or changes in key system directories associated with the UniFi application.

How to Mitigate CVE-2024-42028

Immediate Actions Required

• Review and audit local user accounts
• Reconfigure and harden user permissions
• Isolate affected systems from sensitive resources

Patch Information

Apply the security patch from UniFi Network Application as soon as it becomes available. Monitor the Community Ui Advisory for updates.

Workarounds

Restrict local access to systems and review user account permissions to ensure least privilege.

# Configuration example
echo "ALL ALL=(ALL:ALL) ALL" >> /etc/sudoers.d/restricted