Detection: Splunk Edit User Privilege Escalation

Updated Date: 2024-05-15 ID: 39e1c326-67d7-4c0d-8584-8056354f6593 Author: Rod Soto, Chase Franklin Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies attempts by low-privilege users to escalate their privileges to admin by exploiting the edit_user capability. It detects this activity by analyzing audit trail logs for specific actions such as "change_own_password" and "edit_password" where the info field is "granted" and the user is not an admin or system user. This activity is significant because it indicates potential privilege escalation, which is a critical security concern. If confirmed malicious, this could allow an attacker to gain administrative access, leading to full control over the Splunk environment and potential data breaches.

1`audittrail` action IN ("change_own_password","password_change","edit_password") AND info="granted" AND NOT user IN (admin, splunk-system-user) 
2| stats earliest(_time) as event_time values(index) as index values(sourcetype) as sourcetype values(action) as action values(info) as info by user 
3| `splunk_edit_user_privilege_escalation_filter`

Data Source

Name Platform Sourcetype Source
Splunk Splunk icon Splunk 'splunkd_ui_access' 'splunkd_ui_access.log'

Macros Used

Name Value
audittrail index=_audit sourcetype=audittrail
splunk_edit_user_privilege_escalation_filter search *
splunk_edit_user_privilege_escalation_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
T1548 Abuse Elevation Control Mechanism Defense Evasion
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 abuse of edit_user privilege.

Known False Positives

This search may produce false positives as password changing actions may be part of normal behavior. Operator will need to investigate these actions in order to discern exploitation attempts.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Possible attempt to abuse edit_user function by $user$ 64 80 80
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 audittrail audittrail
Integration ✅ Passing Dataset audittrail audittrail

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