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.

Search

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	Supported App
Splunk	Splunk	`'splunkd_ui_access'`	`'splunkd_ui_access.log'`	N/A

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

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

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

Splunk Vulnerabilities

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

https://research.splunk.com/stories/splunk_vulnerabilities/

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