THIS IS A EXPERIMENTAL DETECTION
This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.
This search provides information to investigate possible remote code execution exploitation via user-supplied Extensible Stylesheet Language Transformations (XSLT), affecting Splunk versions 9.1.x.
- Type: Hunting
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2023-11-16
- Author: Rod Soto, Splunk
- ID: a053e6a6-2146-483a-9798-2d43652f3299
Kill Chain Phase
- CIS 10
1 2 3 4 | rest splunk_server=local /services/data/lookup-table-files/ | fields title author disabled eai:acl.app eai:acl.owner eai:acl.sharing eai:appName eai:data | `splunk_app_for_lookup_file_editing_rce_via_user_xslt_filter`
The SPL above uses the following Macros:
splunk_app_for_lookup_file_editing_rce_via_user_xslt_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
Because there is no way to detect the payload, this search only provides the ability to monitor the creation of lookups which are the base of this exploit. An operator must then investigate suspicious lookups. This search requires ability to perform REST queries. Note that if the Splunk App for Lookup File Editing is not, or was not, installed in the Splunk environment then it is not necessary to run the search as the enviornment was not vulnerable.
Known False Positives
This search will provide information for investigation and hunting of lookup creation via user-supplied XSLT which may be indications of possible exploitation. There will be false positives as it is not possible to detect the payload executed via this exploit.
Associated Analytic Story
|1.0||50||2||Please review $eai:acl.app$ for possible malicious lookups|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1