Detection: Splunk XSS in Save table dialog header in search page

Updated Date: 2024-07-01 ID: a974d1ee-ddca-4837-b6ad-d55a8a239c20 Author: Rod Soto Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies persistent cross-site scripting (XSS) attempts in the 'Save Table' dialog on the Splunk search page. It detects POST requests to the endpoint /en-US/splunkd/__raw/servicesNS/nobody/search/datamodel/model containing potential XSS payloads. This activity is significant because it can allow a remote user with the "power" role to inject malicious scripts, leading to persistent XSS vulnerabilities. If confirmed malicious, this could enable attackers to execute arbitrary scripts in the context of the affected user, potentially leading to data theft, session hijacking, or further exploitation within the Splunk environment.

Search

1`splunkd_webx` method=POST  uri=/*/splunkd/__raw/servicesNS/nobody/search/datamodel/model 
2| table _time host status clientip user uri 
3| `splunk_xss_in_save_table_dialog_header_in_search_page_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_xss_in_save_table_dialog_header_in_search_page_filter	`search *`

splunk_xss_in_save_table_dialog_header_in_search_page_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

Watch for POST requests combined with XSS script strings or obfuscation against the injection point /en-US/splunkd/__raw/servicesNS/nobody/search/datamodel/model.

Known False Positives

If host is vulnerable and XSS script strings are inputted they will show up in search. Not all Post requests are malicious as they will show when users create and save dashboards. This search may produce several results with non malicious POST requests. Only affects Splunk Web enabled instances.

Associated Analytic Story

Splunk Vulnerabilities

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Possible XSS exploitation attempt from $clientip$	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: 3