Splunk protocol impersonation weak encryption simplerequest

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Description

On Splunk version 9 on Python3 client libraries verify server certificates by default and use CA certificate store. This search warns a user about a failure to validate a certificate using python3 request.

• Type: Hunting

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2022-05-24
• Author: Rod Soto, Splunk
• ID: 839d12a6-b119-4d44-ac4f-13eed95412c8

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1588.004	Digital Certificates	Resource Development

Kill Chain Phase

• Weaponization

NIST

• DE.AE

CIS20

• CIS 10

CVE

ID	Summary	CVSS
CVE-2022-32152	Splunk Enterprise peers in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203 did not validate the TLS certificates during Splunk-to-Splunk communications by default. Splunk peer communications configured properly with valid certificates were not vulnerable. However, an attacker with administrator credentials could add a peer without a valid certificate and connections from misconfigured nodes without valid certificates did not fail by default. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.	6.5

Search

`splunk_python` "simpleRequest SSL certificate validation is enabled without hostname verification" 
| stats count by host path 
| `splunk_protocol_impersonation_weak_encryption_simplerequest_filter`

Macros

The SPL above uses the following Macros:

• splunk_python

splunk_protocol_impersonation_weak_encryption_simplerequest_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

• host
• event_message
• path

How To Implement

Must upgrade to Splunk version 9 and Configure TLS host name validation for Splunk Python modules in order to apply this search. Splunk SOAR customers can find a SOAR workbook that walks an analyst through the process of running these hunting searches in the references list of this detection. In order to use this workbook, a user will need to run a curl command to post the file to their SOAR instance such as "curl -u username:password https://soar.instance.name/rest/rest/workbook_template -d @splunk_psa_0622.json". A user should then create an empty container or case, attach the workbook, and begin working through the tasks.

Known False Positives

This search tries to address validation of server and client certificates within Splunk infrastructure, it might produce results from accidental or unintended requests to port 8089.

Associated Analytic Story

• Splunk Vulnerabilities

RBA

Risk Score	Impact	Confidence	Message
40.0	50	80	Failed to validate certificate on $host$

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://www.splunk.com/en_us/product-security
• https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation
• https://www.github.com/splunk/security_content/blob/develop/workbooks/splunk_psa_0622.json

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 1