:warning: 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.

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Description

The following analytic identifies attempts to exploit a vulnerability in Splunk Enterprise versions below 8.2.9, 8.1.12, and 9.0.2, where an authenticated user can execute arbitrary code via the dashboard PDF generation component. It detects this activity by analyzing events in the _internal index with the file=export parameter. This behavior is significant because it indicates a potential code injection attack, which could lead to remote code execution (RCE). If confirmed malicious, an attacker could gain unauthorized access, execute arbitrary commands, and potentially compromise the entire Splunk environment.

  • Type: Hunting

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

  • Last Updated: 2024-05-24
  • Author: Rod Soto
  • ID: b06b41d7-9570-4985-8137-0784f582a1b3

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1210 Exploitation of Remote Services Lateral Movement
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`splunkd_ui` uri_path=*/data/ui/views/* OR uri_path=*saved/searches/* 
| dedup uri_path 
| eval URL=urldecode("uri_path")
| rex field=URL "\/saved\/searches\/(?<NAME>[^\/]*)" 
| rex field=URL "\/data\/ui\/views\/(?<NAME1>[^\/]*)" 
| eval NAME=NAME."( Saved Search )",NAME1=NAME1."( Dashboard )" 
| eval NAME=coalesce(NAME,NAME1) 
| eval STATUS=case(match(status,"2\d+"),"SUCCESS",match(status,"3\d+"),"REDIRECTION",match(status,"4\d+") OR match(status,"5\d+"),"ERROR") 
| stats list(NAME) as DASHBOARD_TITLE,list(method) as HTTP_METHOD,list(status) as Status_Code,list(STATUS) as STATUS by user 
| rename user as User 
| `splunk_code_injection_via_custom_dashboard_leading_to_rce_filter`

Macros

The SPL above uses the following Macros:

:information_source: splunk_code_injection_via_custom_dashboard_leading_to_rce_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
  • clientip
  • uri
  • uri_path
  • method
  • status

How To Implement

This detection does not require you to ingest any new data. The detection does require the ability to search the _internal index.

Known False Positives

Not all exports and downloads are malicious, special attention must be put as well on /en-US/splunkd/__raw/services/pdfgen/render in the context of this search.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 Potential exploitation of Code Injection via Dashboard PDF generation.

: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

source | version: 2