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Description

In Splunk Enterprise versions below 8.1.13, 8.2.10, and 9.0.4, the lookup table uploads let a user upload lookup tables with unnecessary filename extensions. Lookup table file extensions may now only be one of .csv, .csv.gz, .kmz, .kml, .mmdb, or .mmdb.gz. This search provides user activity focus on uploads which aims to help hunt for malicious file uploads.

  • Type: TTP

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

  • Last Updated: 2023-02-14
  • Author: Rod Soto, Splunk
  • ID: b7d1293f-e78f-415e-b5f6-443df3480082

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1189 Drive-by Compromise Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 10
CVE
ID Summary CVSS
CVE-2023-22937 In Splunk Enterprise versions below 8.1.13, 8.2.10, and 9.0.4, the lookup table upload feature let a user upload lookup tables with unnecessary filename extensions. Lookup table file extensions may now be one of the following only: .csv, .csv.gz, .kmz, .kml, .mmdb, or .mmdb.gzl. None 


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`splunkda` method IN ("POST", "DELETE") uri_path=/servicesNS/*/ui/views/* 
| eval activity = case( method=="POST" AND like( uri_path , "%/acl" ) , "Permissions Update", method=="POST" AND NOT like( uri_path , "%/acl" ) , "Edited" , method=="DELETE" , "Deleted" ) 
| rex field=uri_path "(?<user_and_app>.*?)\/ui\/views/(?<dashboard_encoded>.*)" 
| eval dashboard = urldecode( dashboard_encoded ) 
| table _time, uri_path, user, dashboard, activity, uri_path 
| `splunk_unnecessary_file_extensions_allowed_by_lookup_table_uploads_filter`

Macros

The SPL above uses the following Macros:

:information_source: splunk_unnecessary_file_extensions_allowed_by_lookup_table_uploads_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.

  • user
  • method
  • uri_path

How To Implement

Requires access to internal splunkd_access.

Known False Positives

This is a hunting search, the search provides information on upload, edit, and delete activity on Lookup Tables. Manual investigation is necessary after executing search. This search will produce false positives as payload cannot be directly discerned.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 Potential lookup template injection attempt from $user$ on lookup table at path $uri_path$

:information_source: 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

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

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