CVE-2024-0213: Trellix Agent Privilege Escalation Flaw

CVE-2024-0213 Overview

CVE-2024-0213 is a buffer overflow vulnerability affecting Trellix Agent (TA) for Linux and macOS prior to version 5.8.1. This security flaw enables a local user to exploit a memory corruption issue in the TA service, which runs with root privileges, potentially leading to elevated permissions or a Denial of Service (DoS) condition. Additionally, successful exploitation may result in the disabling of event reporting to ePO (ePolicy Orchestrator), caused by failure to validate input from a file correctly.

Critical Impact

Local attackers with low privileges can exploit this buffer overflow to gain root-level access on affected Linux and macOS systems, compromise endpoint security monitoring, and disrupt event reporting to centralized management.

Affected Products

• Trellix Agent for Linux (versions prior to 5.8.1)
• Trellix Agent for macOS (versions prior to 5.8.1)

Discovery Timeline

• 2024-01-09 - CVE-2024-0213 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-0213

Vulnerability Analysis

This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), commonly known as a classic buffer overflow. The flaw exists within the Trellix Agent service, which operates with elevated (root) privileges on both Linux and macOS platforms. The vulnerability stems from improper validation of input when processing data from files, allowing an attacker to trigger a memory corruption condition.

The local attack vector means an attacker must have some level of access to the target system before exploitation. However, the low complexity of exploitation and the potential to escalate from limited user privileges to full root access makes this a significant security concern. Successful exploitation can lead to complete compromise of system confidentiality, integrity, and availability. A secondary impact is the potential disruption of security monitoring capabilities, as the TA service failure can disable event reporting to the centralized ePO management console.

Root Cause

The root cause of CVE-2024-0213 is improper input validation in the Trellix Agent service. Specifically, the service fails to properly validate the size of input data read from files before copying it into fixed-size memory buffers. This oversight allows an attacker to craft malicious input that exceeds buffer boundaries, overwriting adjacent memory regions. Since the TA service runs with root privileges, successful memory corruption can be leveraged to execute arbitrary code in a privileged context or crash the service entirely.

Attack Vector

The attack vector for CVE-2024-0213 is local, requiring an authenticated user with low-level privileges on the target system. The attacker would need to:

1. Gain initial access to a system running a vulnerable version of Trellix Agent
2. Identify or create a file that the TA service processes
3. Craft malicious input that triggers the buffer overflow condition
4. Execute the attack to either escalate privileges to root or cause service disruption

The vulnerability does not require user interaction and can be exploited with low complexity once local access is achieved. The scope is unchanged, meaning the impact is confined to the vulnerable component's security context, though that context is root-level access.

The exploitation mechanism involves providing oversized input data that the TA service reads without proper bounds checking. When this data is copied into a fixed-size buffer, it overflows into adjacent memory, potentially overwriting critical data structures or function pointers. This memory corruption can be leveraged to redirect execution flow and gain elevated privileges. For detailed technical information, refer to the Trellix Security Advisory SB10416.

Detection Methods for CVE-2024-0213

Indicators of Compromise

• Unexpected crashes or restarts of the Trellix Agent service (masvc process)
• Missing or gaps in ePO event reporting from affected endpoints
• Unusual file access patterns targeting TA configuration or input files
• Process spawning anomalies from the Trellix Agent service with unexpected child processes

Detection Strategies

• Monitor for abnormal behavior of the Trellix Agent service, including unexpected terminations or restarts
• Review system logs for segmentation faults or memory access violations associated with TA processes
• Implement file integrity monitoring on directories and files processed by the Trellix Agent
• Deploy endpoint detection rules to identify privilege escalation attempts originating from the TA service context

Monitoring Recommendations

• Configure alerting for ePO connectivity failures or extended periods without endpoint check-ins
• Enable verbose logging on Trellix Agent services to capture potential exploitation attempts
• Monitor for unusual process creation chains where root-level processes are spawned unexpectedly
• Utilize SentinelOne's behavioral AI to detect anomalous activity patterns consistent with privilege escalation

How to Mitigate CVE-2024-0213

Immediate Actions Required

• Upgrade Trellix Agent to version 5.8.1 or later on all affected Linux and macOS systems immediately
• Audit current Trellix Agent installations to identify systems running vulnerable versions (prior to 5.8.1)
• Restrict local user access on systems with vulnerable TA installations until patching is complete
• Monitor affected systems for signs of exploitation while remediation is in progress

Patch Information

Trellix has released a security update addressing this vulnerability. Administrators should upgrade Trellix Agent to version 5.8.1 or later to remediate CVE-2024-0213. The official security advisory with patch details is available at Trellix Security Advisory SB10416. Organizations should prioritize patching systems based on their exposure risk and criticality.

Workarounds

• Implement strict access controls to limit local user access on systems running Trellix Agent
• Monitor and restrict file write permissions to directories containing files processed by the TA service
• Consider network segmentation to limit the impact of potential compromise on affected endpoints
• Enable enhanced audit logging to detect exploitation attempts while awaiting patch deployment

# Check current Trellix Agent version on Linux/macOS
/opt/McAfee/agent/bin/maconfig -version

# Verify TA service status
systemctl status masvc

# Review TA service logs for anomalies
tail -f /var/McAfee/agent/logs/masvc.log