Detection: Splunk Low Privilege User Can View Hashed Splunk Password

Updated Date: 2024-05-29 ID: a1be424d-e59c-4583-b6f9-2dcc23be4875 Author: Rod Soto, Eric McGinnis, Chase Franklin Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies low-privilege users attempting to view hashed Splunk passwords by querying the conf-user-seed REST endpoint. It leverages data from the splunkd_web logs, specifically monitoring access to the conf-user-seed endpoint. This activity is significant because it can indicate an attempt to escalate privileges by obtaining hashed credentials, potentially leading to admin account takeover. If confirmed malicious, this could allow an attacker to gain administrative control over the Splunk instance, compromising the entire environment's security.

Search

1`splunkd_web` uri="*/servicesNS/nobody/system/configs/conf-user-seed*" 
2| stats earliest(_time) as event_time values(method) as method values(status) as status values(clientip) as clientip values(useragent) as useragent values(file) as file by user 
3| convert ctime(*time) 
4| `splunk_low_privilege_user_can_view_hashed_splunk_password_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_web	`index=_internal sourcetype=splunk_web_access`
splunk_low_privilege_user_can_view_hashed_splunk_password_filter	`search *`

splunk_low_privilege_user_can_view_hashed_splunk_password_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
T1212	Exploitation for Credential Access	Credential Access

KillChainPhase.EXPLOITAITON

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
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 detection does not require you to ingest any new data. The detection does require the ability to search the _audit index. This detection may assist in efforts to discover attempts to access con-user-seed file content.

Known False Positives

This search may produce false positives as accounts with high privileges may access this file. Operator will need to investigate these actions in order to discern exploitation attempts.

Associated Analytic Story

Splunk Vulnerabilities

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Attempt to access Splunk hashed password file 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://advisory.splunk.com/

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