This hunting search provides information on detecting a vulnerability In Splunk Enterprise versions lower than 8.1.14, 8.2.12, 9.0.6, and 9.1.1, an attacker can use the printf SPL function to perform a denial of service against the Splunk Enterprise instance.
- Type: Hunting
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2023-08-30
- Author: Rod Soto, Eric McGinnis, Splunk
- ID: 78b48d08-075c-4eac-bd07-e364c3780867
Kill Chain Phase
- Actions On Objectives
- CIS 10
1 2 3 4 `audit_searches` "*makeresults * eval * fieldformat *printf*" user!="splunk_system_user" search!="*audit_searches*" | stats count by user splunk_server host search | convert ctime(*time) |`splunk_dos_via_printf_search_function_filter`
The SPL above uses the following Macros:
splunk_dos_via_printf_search_function_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
This search requires the ability to search internal indexes.
Known False Positives
This search may produces false positives, analyst most focuse in the use of printf conversion function of eval to craft an expression that splunkd cannot interpret correctly causing it to crash.
Associated Analytic Story
|100.0||100||100||Possible denial of service attack against $host$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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