Detection: Detect Baron Samedit CVE-2021-3156 via OSQuery

EXPERIMENTAL DETECTION

This detection status is set to experimental. The Splunk Threat Research team has not yet fully tested, simulated, or built comprehensive datasets for this detection. As such, this analytic is not officially supported. If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2024-10-17 ID: 1de31d5d-8fa6-4ee0-af89-17069134118a Author: Shannon Davis, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the execution of the "sudoedit -s *" command, which is associated with the Baron Samedit CVE-2021-3156 heap-based buffer overflow vulnerability. This detection leverages the osquery_process data source to identify instances where this specific command is run. This activity is significant because it indicates an attempt to exploit a known vulnerability that allows privilege escalation. If confirmed malicious, an attacker could gain full control of the system, execute arbitrary code, or access sensitive data, leading to potential data breaches and system disruptions.

Search

1`osquery_process` 
2| search "columns.cmdline"="sudoedit -s \\*" 
3| `detect_baron_samedit_cve_2021_3156_via_osquery_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name	Value
osquery_process	`eventtype="osquery-process"`
detect_baron_samedit_cve_2021_3156_via_osquery_filter	`search *`

detect_baron_samedit_cve_2021_3156_via_osquery_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
T1068	Exploitation for Privilege Escalation	Privilege Escalation

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT28

APT29

APT32

APT33

BITTER

Cobalt Group

FIN6

FIN8

LAPSUS$

MoustachedBouncer

PLATINUM

Scattered Spider

Threat Group-3390

Tonto Team

Turla

Volt Typhoon

Whitefly

ZIRCONIUM

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 Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

OSQuery installed and configured to pick up process events (info at https://osquery.io) as well as using the Splunk OSQuery Add-on https://splunkbase.splunk.com/app/4402. The vulnerability is exposed when a non privledged user tries passing in a single \ character at the end of the command while using the shell and edit flags.

Known False Positives

unknown

Associated Analytic Story

Baron Samedit CVE-2021-3156

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
tbd	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.

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	Not Applicable	N/A	N/A	N/A
Unit	❌ Failing	N/A	`N/A`	`N/A`
Integration	❌ Failing	N/A	`N/A`	`N/A`

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: 4