ID | Technique | Tactic |
---|---|---|
T1210 | Exploitation of Remote Services | Lateral Movement |
Detection: Splunk App for Lookup File Editing RCE via User XSLT
EXPERIMENTAL DETECTION
This detection status is set to experimental. The Splunk Threat Research team has not yet fully tested, simulated, or built comprehensive datasets for this detection. As such, this analytic is not officially supported. If you have any questions or concerns, please reach out to us at research@splunk.com.
Description
The following analytic identifies the creation of lookup files in Splunk, which could indicate an attempt to exploit remote code execution via user-supplied XSLT. It leverages REST API queries to monitor the creation of these lookups, focusing on fields such as title, author, and access control lists. This activity is significant because it targets a known vulnerability in Splunk versions 9.1.x, potentially allowing attackers to execute arbitrary code. If confirmed malicious, this could lead to unauthorized code execution, compromising the integrity and security of the Splunk environment.
Search
1
2| rest splunk_server=local /services/data/lookup-table-files/
3| fields title author disabled eai:acl.app eai:acl.owner eai:acl.sharing eai:appName eai:data
4| `splunk_app_for_lookup_file_editing_rce_via_user_xslt_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
N/A | N/A | N/A | N/A | N/A |
Macros Used
Name | Value |
---|
| splunk_app_for_lookup_file_editing_rce_via_user_xslt_filter | search *
|
splunk_app_for_lookup_file_editing_rce_via_user_xslt_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Risk Event | False |
Implementation
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
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Please review $eai:acl.app$ for possible malicious lookups | 1 | 50 | 2 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | Not Applicable | N/A | N/A | N/A |
Unit | ❌ Failing | N/A | N/A |
N/A |
Integration | ❌ Failing | N/A | N/A |
N/A |
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: GitHub | Version: 2