Detection: Splunk Image File Disclosure via PDF Export in Classic Dashboard

REMOVED DETECTION

This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.

Reason: Detection is deprecated as the associated CVEs have been patched in the latest Splunk release.

Removed in version: 5.6.0

If you have any questions or concerns, please reach out to us at research@splunk.com.

Description

In Splunk Enterprise versions 9.3.0, 9.2.3, and 9.1.6, a low-privileged user that does not hold the “admin” or “power” Splunk roles could view images on the host machine using the PDF export feature in Splunk classic dashboards.

 1```Search for any PDFs that have been generated```
 2index=_internal sourcetype=splunk_pdfgen "Generated pdf" 
 3```Extract a potential Dashboard Filename```
 4
 5| rex field=filename "(?<title>.*)-[0-9]{4}-[0-9]{1,2}-[0-9]{1,2}.pdf" 
 6```Join this with all dashboards. Potentially vulnerable dashbaords MUST be classic (version 1.1) AND contain at least one <img...> tag```
 7
 8| join type=inner title 
 9    [
10| rest /servicesNS/-/-/data/ui/views 
11    
12| search eai:data="*<img*" version="1.1"] 
13
14| stats count min(_time) as earliestTime max(_time) as latestTime by author eai:acl.app label title eai:data
15
16| `security_content_ctime(earliestTime)`
17
18| `security_content_ctime(latestTime)`
19
20| `splunk_image_file_disclosure_via_pdf_export_in_classic_dashboard_filter`

Data Source

Name Platform Sourcetype Source
Splunk Splunk icon Splunk 'splunkd_ui_access' 'splunkd_ui_access.log'

Macros Used

Name Value
[Search for any PDFs that have been generated](https://github.com/splunk/security_content/blob/develop/macros/Search for any PDFs that have been generated.yml) ``
index=_internal sourcetype=splunk_pdfgen "Generated pdf"
](https://github.com/splunk/security_content/blob/develop/macros/
index=_internal sourcetype=splunk_pdfgen "Generated pdf"
.yml) ``
splunk_image_file_disclosure_via_pdf_export_in_classic_dashboard_filter ``
splunk_image_file_disclosure_via_pdf_export_in_classic_dashboard_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1087 Account Discovery Discovery

CVE

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule N/A
Earliest Time N/A
Latest Time N/A
Schedule Window N/A
Creates Finding (Notable) No
Creates Intermediate Finding (Risk Event) No
Hunting detections do not generate a Finding (Notable) or Intermediate Findings (Risk Events).

Implementation

Need to access to REST API.

Known False Positives

This is a hunting search and operator must identify indicators of local host image source such as UNC paths ('C:'', '//'') in order to identify potential exploitation of this vulnerability.

Associated Analytic Story

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Not Applicable N/A N/A N/A
Unit Not Applicable N/A N/A N/A

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: GitHub |

Version: 5