Splunk unnecessary file extensions allowed by lookup table uploads
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
Kill Chain Phase
- CIS 3
- CIS 5
- CIS 16
|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. For more information on lookup table files, see About lookups.||None|
1 2 3 4 5 6 `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`
The SPL above uses the following Macros:
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.
List of fields required to use this analytic.
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
|25.0||50||50||Potential lookup template injection attempt from $user$ on lookup table at path $uri_path$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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