ID | Technique | Tactic |
---|---|---|
T1190 | Exploit Public-Facing Application | Initial Access |
Detection: ConnectWise ScreenConnect Path Traversal Windows SACL
Description
The following analytic detects attempts to exploit the ConnectWise ScreenConnect CVE-2024-1708 vulnerability using Windows SACL EventCode 4663. It identifies path traversal attacks by monitoring file system events related to the ScreenConnect service. This activity is significant as it allows unauthorized access to sensitive files and directories, potentially leading to data exfiltration or arbitrary code execution. If confirmed malicious, attackers could gain unauthorized access to critical data or execute harmful code, compromising the integrity and security of the affected system. Immediate remediation by updating to version 23.9.8 or above is recommended.
Search
1`wineventlog_security` EventCode=4663 ProcessName=*\\ScreenConnect.Service.exe file_path IN ("*\\ScreenConnect\\App_Extensions\\*") file_name IN ("*.aspx","*.ashx")
2| stats count min(_time) as firstTime max(_time) as lastTime by ObjectName ObjectType ProcessName AccessMask process_id EventCode Computer Caller_User_Name
3| rename Computer as dest Caller_User_Name as user ProcessName as process_name
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)`
6| `connectwise_screenconnect_path_traversal_windows_sacl_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
Windows Event Log Security 4663 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Security' |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
connectwise_screenconnect_path_traversal_windows_sacl_filter | search * |
connectwise_screenconnect_path_traversal_windows_sacl_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 |
Implementation
To implement the following query, enable SACL auditing for the ScreenConnect directory(ies). With this data, the following analytic will work correctly. A GIST is provided in the references to assist with enabling SACL Auditing.
Known False Positives
False positives should be limited as the analytic is specific to ScreenConnect path traversal attempts. Tune as needed, or restrict to specific hosts if false positives are encountered.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A path traversal attack against ScreenConnect has been detected on $dest$. | 100 | 100 | 100 |
References
-
https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4663
-
https://www.huntress.com/blog/detection-guidance-for-connectwise-cwe-288-2
-
https://www.connectwise.com/company/trust/security-bulletins/connectwise-screenconnect-23.9.8
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | XmlWinEventLog:Security |
XmlWinEventLog |
Integration | ✅ Passing | Dataset | XmlWinEventLog:Security |
XmlWinEventLog |
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: 3