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Description

The following analytic detects the exploitation of an absolute path traversal vulnerability in Splunk Enterprise versions lower than 8.2.12, 9.0.6, and 9.1.1, where an attacker can execute arbitrary code located on a separate disk. It leverages logs from the splunk_python macro, specifically looking for the runshellscript command with a specific argument count and path pattern. This activity is significant as it indicates a potential exploitation attempt that could lead to unauthorized code execution. If confirmed malicious, this could allow an attacker to gain control over the Splunk instance, leading to data breaches or further system compromise.

  • Type: Hunting

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

  • Last Updated: 2024-05-17
  • Author: Rod Soto
  • ID: 356bd3fe-f59b-4f64-baa1-51495411b7ad

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1083 File and Directory Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`splunk_python` *runshellscript*  
| eval log_split=split(_raw, "runshellscript: ") 
| eval array_raw = mvindex(log_split,1) 
| eval data_cleaned=replace(replace(replace(array_raw,"\[",""),"\]",""),"'","") 
| eval array_indices=split(data_cleaned,",") 
| eval runshellscript_args_count=mvcount(array_indices) 
| where runshellscript_args_count = 10 
| eval interpreter=mvindex(array_indices,0) 
| eval targetScript=mvindex(array_indices,1) 
| eval targetScript != "*C:*" 
| stats count min(_time) as firstTime max(_time) as lastTime by splunk_server interpreter targetScript 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `splunk_absolute_path_traversal_using_runshellscript_filter`

Macros

The SPL above uses the following Macros:

:information_source: splunk_absolute_path_traversal_using_runshellscript_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.

  • search

How To Implement

Must have access to internal indexes. Only applies to Splunk on Windows versions.

Known False Positives

The command runshellscript can be used for benign purposes. Analyst will have to review the searches and determined maliciousness specially by looking at targeted script.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
35.0 50 70 Possible attack against splunk_server $splunk_server$ through abuse of the runshellscript command

: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