Detection: Splunk XSS Privilege Escalation via Custom Urls in Dashboard

Updated Date: 2024-10-17 ID: 01e1e386-7656-4f36-a55a-52fe39b04a96 Author: Rod Soto, Chase Franklin Type: Hunting Product: Splunk Enterprise Security

Description

This is a composed hunting search that looks for POST requests to splunk_internal_metrics/data/ui/views which can be used to elevate privileges on the Splunk server via custom urls. The way to find privilege escalation is by looking at created users with high privielges after payload has been executed. This search looks at POST request and then looks at created users privileges.

 1`splunkd_ui` method=POST /*/data/ui/views* 
 2| stats values(method) as method by _time index, sourcetype, host 
 3| eval event="post_request" 
 4| append [
 5| search `audittrail` action="edit_user" operation="create" 
 6| rex field=_raw "object=\"(?<newUser>.*)\"" 
 7| stats count values(operation) as operation values(splunk_server) as splunk_server values(user) as user by _time index, sourcetype, host, newUser 
 8| eval event="create_user"] 
 9| sort - _time 
10| transaction host startswith=event="post_request" endswith=event="create_user" maxspan=10m 
11| table _time index, sourcetype, host, method, user, splunk_server, operation, event, newUser eventcount 
12| `splunk_xss_privilege_escalation_via_custom_urls_in_dashboard_filter`

Data Source

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

Macros Used

Name Value
audittrail index=_audit sourcetype=audittrail
splunk_xss_privilege_escalation_via_custom_urls_in_dashboard_filter search *
splunk_xss_privilege_escalation_via_custom_urls_in_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
T1189 Drive-by Compromise Initial Access
KillChainPhase.DELIVERY
NistCategory.DE_AE
Cis18Value.CIS_10
APT19
APT28
APT32
APT37
APT38
Andariel
Axiom
BRONZE BUTLER
CURIUM
Daggerfly
Dark Caracal
Darkhotel
Dragonfly
Earth Lusca
Elderwood
Lazarus Group
Leafminer
Leviathan
Machete
Magic Hound
Mustard Tempest
PLATINUM
PROMETHIUM
Patchwork
RTM
Threat Group-3390
Transparent Tribe
Turla
Windigo
Windshift
Winter Vivern

Default Configuration

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

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Risk Event False
This configuration file applies to all detections of type hunting.

Implementation

Requires access to internal indexes _audit and _internal.

Known False Positives

This is a hunting search and requires operator to search for specific indicators of user creation in proximity to POST requests against vulnerable endpoint. It is not possible to detect payload during runtime.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Possible XSS attack and privilege escalation via custom urls in dashboard against $host$ 5 10 50
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset /opt/splunk/var/log/splunk/splunkd_ui_access.log splunkd_ui_access
Integration ✅ Passing Dataset /opt/splunk/var/log/splunk/splunkd_ui_access.log splunkd_ui_access

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: 2