Detection: Splunk Reflected XSS in the templates lists radio

Updated Date: 2024-05-23 ID: d532d105-c63f-4049-a8c4-e249127ca425 Author: Rod Soto, Chase Franklin Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies potential reflected cross-site scripting (XSS) attempts in Splunk versions below 8.1.12, 8.2.9, and 9.0.2. It detects when a query parameter with output_mode=radio is used in a URI, leveraging splunkd_webx logs with status 200 and non-null URI queries. This activity is significant as it can indicate an attempt to exploit a known vulnerability, potentially allowing attackers to execute arbitrary JavaScript in the context of the user's browser. If confirmed malicious, this could lead to unauthorized actions, data theft, or further compromise of the affected Splunk instance.

1`splunkd_webx` user=admin status=200 uri=*/lists/entities/x/ui/views* uri_query!=null 
2| stats count earliest(_time) as event_time values(status) as status values(clientip) as clientip by index, sourcetype, _time, host, user, uri 
3| `splunk_reflected_xss_in_the_templates_lists_radio_filter`

Data Source

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

Macros Used

Name Value
splunkd_webx index=_internal sourcetype=splunk_web_access
splunk_reflected_xss_in_the_templates_lists_radio_filter search *
splunk_reflected_xss_in_the_templates_lists_radio_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

This vulnerability only affects instances with Splunk Web enabled. 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

This search may produce false positives as it is difficult to pinpoint all possible XSS injection characters in a single search string. Special attention is required to "en-US/list/entities/x/ui/views" which is the vulnerable injection point.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Potential XSS exploitation against radio template by $user$ 25 50 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/web_access.log splunk_web_access
Integration ✅ Passing Dataset /opt/splunk/var/log/splunk/web_access.log splunk_web_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