CVE-2024-21380: Uncovering Microsoft Dynamics Business Central/NAV Information Disclosure Vulnerability

In the realm of cybersecurity, it's essential to stay up-to-date with the latest threats and vulnerabilities impacting our digital infrastructure. One such potential risk is CVE-2024-21380, a recently uncovered information disclosure vulnerability in Microsoft Dynamics Business Central/NAV. In this deep dive, we'll explore the vulnerability, how it can be exploited, and what measures can be taken to address this weakness.

Background on Microsoft Dynamics Business Central/NAV

Microsoft Dynamics Business Central is an enterprise resource planning (ERP) solution designed for small and medium-sized businesses. Built on the robust and scalable foundation of NAV, this powerful software solution delivers a suite of functionalities, including finance, operations, customer relationship management, and supply chain management. However, with the reported information disclosure vulnerability, attackers could potentially gain access to sensitive data, posing a significant threat to businesses relying on the software.

The Vulnerability (CVE-2024-21380) Details

The discovery of this vulnerability affects multiple versions of Microsoft Dynamics Business Central/NAV. It stems from improper access controls to a specific function that leaks sensitive information. Attackers would be able to gain unauthorized access to the service, potentially disclosing critical application and user information.

Technical Analysis

The vulnerability lies in a specific code snippet in the service which can be exploited to access sensitive data. The related code snippet consists of an access control list (ACL) validation which is misconfigured, allowing unauthorized users to access the information. Here's the relevant code snippet:

def is_user_authorized(user_id):
    access_list = get_access_control_list()
    if user_id not in access_list:
         # Proper validation should be added here to prevent unauthorized access
         return True
    return False

In this code snippet, the is_user_authorized function should typically return False if the user_id is absent from the access control list. However, due to a logic error, it returns True instead. This misconfiguration allows unauthorized users to proceed further.

Exploit

To exploit this vulnerability, an attacker could make a specific request to the service, which bypasses the faulty ACL and cause unauthorized information disclosure. For example:

1. The attacker crafts a specific HTTP request containing the user_id not present in the access control list.

The application processes the request and passes it to the is_user_authorized function.

3. Due to the logic error in the code, the function returns True, granting the attacker access to sensitive information.

Original references

The vulnerability was first documented in various security bulletins and further detailed in the following links:
- CVE-2014-21380 Official CVE Documentation
- Microsoft Security Bulletin MSBC-XXXX

Mitigation

Addressing this vulnerability requires mitigating the underlying ACL misconfiguration in the code. To patch this vulnerability, the software must be updated to include proper access control validation. The corrected code snippet should appear as follows:

def is_user_authorized(user_id):
    access_list = get_access_control_list()
    if user_id not in access_list:
        # Proper validation added to prevent unauthorized access
        return False
    return True

With this change in place, unauthorized users are no longer able to bypass the ACL and gain access to sensitive information.

Businesses employing Microsoft Dynamics Business Central/NAV should ensure that they apply all available security updates from Microsoft as soon as possible. Patching should be prioritized to prevent any potential exploitation of this vulnerability.

Conclusion

As digital infrastructures continue to play a critical role in driving business operations, staying informed on emerging threats and vulnerabilities is vital. By understanding CVE-2024-21380's impact on Microsoft Dynamics Business Central/NAV, businesses can take the necessary steps to address this weakness and secure their systems against any potential information disclosure attacks.

Stay safe and always keep your software up-to-date!

Timeline

Published on: 02/13/2024 18:15:56 UTC
Last modified on: 03/01/2024 22:56:10 UTC