The security vulnerability CVE-2022-43570 has been detected in various versions of Splunk Enterprise. This security flaw arises due to an XML External Entity (XXE) injection vulnerability, which occurs when an authenticated user uses a custom view in Splunk Web. This vulnerability affects Splunk Enterprise versions below 8.1.12, 8.2.9, and 9..2.

In this post, we will look into this vulnerability, explain what XXE injection is, and provide information about potential exploitation methods - including detailed exploit code snippets. We will also include links to the relevant original references so that you can look more in-depth into this issue.

What is XXE Injection?
XML External Entity (XXE) injection is a type of vulnerability that exploits weaknesses in XML parsers to trick them into embedding external documents with malicious payloads. This can lead to unauthorized access to sensitive data and may even enable attackers to compromise an affected system.

Exploit Detail

The XXE injection vulnerability in Splunk Enterprise allows an authenticated user to exploit the weakness in XML parsing using a custom view. When an attacker creates a custom view containing a crafted XML payload, Splunk's XML parser can inadvertently include externally referenced entities (such as local files on the server). This causes the server to embed the incorrect documents, leading to potential exposure of sensitive data or unauthorized system access.

Code Snippet

The following is an example of an XML payload that could be used by an attacker to exploit CVE-2022-43570:

<?xml version="1." encoding="UTF-8"?>
<!DOCTYPE root [
 <!ENTITY xxe SYSTEM "file:///etc/passwd"> 
]>
<dashboard>
  <label>XXE Injection PoC</label>
  <row>
    <panel>
      <html>
        <p>&xxe;</p>
      </html>
    </panel>
  </row>
</dashboard>

In this example, the entity xxe points to a sensitive file on the server, /etc/passwd. When the malicious XML payload is parsed, the contents of the /etc/passwd file get included in the output, exposing sensitive data.

Original References

1. Splunk Security Advisory - SPL-209923
2. CVE Database Entry - CVE-2022-43570

Mitigation and Recommendations

Splunk has released security updates to address this vulnerability in the affected Splunk Enterprise versions:

Update to Splunk Enterprise version 9..2 or later

If you are unable to update to these versions immediately, please consider using the following recommendations as temporary workarounds:

Conclusion

CVE-2022-43570 is a critical vulnerability affecting Splunk Enterprise, which, if left unaddressed, can lead to unauthorized access to sensitive data and system compromise. It is essential to apply the security updates released by Splunk or implement the recommended workarounds as soon as possible to mitigate the risk.

Timeline

Published on: 11/04/2022 23:15:00 UTC
Last modified on: 11/08/2022 19:43:00 UTC