Detection: Splunk RCE via Splunk Secure Gateway Splunk Mobile alerts feature

Updated Date: 2024-05-16 ID: baa41f09-df48-4375-8991-520beea161be Author: Rod Soto Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies potential exploitation attempts against the Splunk Secure Gateway App's Mobile Alerts feature in Splunk versions 9.0, 8.2.x, and 8.1.x. It detects suspicious activity by monitoring requests to the mobile alerts endpoint using specific URI paths and query parameters. This activity is significant because an authenticated user could exploit this vulnerability to execute arbitrary operating system commands remotely. If confirmed malicious, this could lead to unauthorized code execution, compromising the integrity and security of the Splunk environment.

Search

1`splunkda` uri_path="/servicesNS/nobody/splunk_secure_gateway/storage/collections/data/mobile_alerts*" sort="notification.created_at:-1" 
2| table  clientip file host method uri_query sort 
3| `splunk_rce_via_splunk_secure_gateway__splunk_mobile_alerts_feature_filter`

Data Source

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

Macros Used

Name	Value
splunkda	`index=_internal sourcetype=splunkd_access`
splunk_rce_via_splunk_secure_gateway__splunk_mobile_alerts_feature_filter	`search *`

splunk_rce_via_splunk_secure_gateway__splunk_mobile_alerts_feature_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
T1210	Exploitation of Remote Services	Lateral Movement

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

APT28

Dragonfly

Earth Lusca

FIN7

Fox Kitten

MuddyWater

Threat Group-3390

Tonto Team

Wizard Spider

menuPass

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 search only applies if Splunk Mobile Gateway is deployed in the vulnerable Splunk versions.

Known False Positives

This detection does not require you to ingest any new data. The detection does require the ability to search the _internal index. Focus of this search is "uri_path=/servicesNS/nobody/splunk_secure_gateway/storage/collections/data/mobile_alerts*" which is the injection point.

Associated Analytic Story

Splunk Vulnerabilities

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Possible exploitation attempt from $clientip$	81	90	90

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://www.splunk.com/en_us/product-security.html

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_access.log`	`splunkd_access`
Integration	✅ Passing	Dataset	`/opt/splunk/var/log/splunk/splunkd_access.log`	`splunkd_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