Detection: Splunk Stored XSS via Specially Crafted Bulletin Message

Date: 2024-07-01 ID: fd852b27-1882-4505-9f2c-64dfb96f4fc1 Author: Rod Soto Type: Hunting Product: Splunk Enterprise Security

Description

The following hunting detection provides fields related to /service/messages endpoints where specially crafted bulletin message can exploit stored XSS.

1
2| rest /services/messages 
3| search message="*http*" 
4| table id author message title 
5| `splunk_stored_xss_via_specially_crafted_bulletin_message_filter`

Data Source

Name Platform Sourcetype Source Supported App
Splunk Splunk icon Splunk 'splunkd_ui_access' 'splunkd_ui_access.log' N/A

Macros Used

Name Value

| splunk_stored_xss_via_specially_crafted_bulletin_message_filter | search * |

splunk_stored_xss_via_specially_crafted_bulletin_message_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

Default Configuration

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

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

Implementation

Need access to Splunk REST api data via search.

Known False Positives

Must look at messages field and find malicious suspicious characters or hyperlinks. Not all requests to this endpoint will be malicious.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Please investigate $message for possible XSS attack in bulletin message $message$ 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 _json _json
Integration ✅ Passing Dataset _json _json

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: 1