Detection: Ivanti Connect Secure System Information Access via Auth Bypass

Updated Date: 2024-11-15 ID: d51c13dd-a232-4c83-a2bb-72ab36233c5d Author: Michael Haag, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic identifies attempts to exploit the CVE-2023-46805 and CVE-2024-21887 vulnerabilities in Ivanti Connect Secure. It detects GET requests to the /api/v1/totp/user-backup-code/../../system/system-information URI, which leverage an authentication bypass to access system information. The detection uses the Web datamodel to identify requests with a 200 OK response, indicating a successful exploit attempt. This activity is significant as it reveals potential unauthorized access to sensitive system information. If confirmed malicious, attackers could gain critical insights into the system, facilitating further exploitation and compromise.

1
2| tstats count min(_time) as firstTime max(_time) as lastTime from datamodel=Web where Web.url="*/api/v1/totp/user-backup-code/../../system/system-information*" Web.http_method=GET Web.status=200 by Web.src, Web.dest, Web.http_user_agent, Web.url 
3| `drop_dm_object_name("Web")` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `ivanti_connect_secure_system_information_access_via_auth_bypass_filter`

Data Source

Name Platform Sourcetype Source
Suricata N/A 'suricata' 'suricata'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
ivanti_connect_secure_system_information_access_via_auth_bypass_filter search *
ivanti_connect_secure_system_information_access_via_auth_bypass_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
T1190 Exploit Public-Facing Application Initial Access
Delivery
DE.AE
CIS 13

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 True
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

This detection requires the Web datamodel to be populated from a supported Technology Add-On like Suricata, Splunk for Apache, Splunk for Nginx, or Splunk for Palo Alto.

Known False Positives

This analytic is limited to HTTP Status 200; adjust as necessary. False positives may occur if the URI path is IP-restricted or externally blocked. It's recommended to review the context of the alerts and adjust the analytic parameters to better fit the specific environment.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Possible exploitation of CVE-2023-46805 and CVE-2024-21887 against $dest$.

Risk Object Risk Object Type Risk Score Threat Objects
dest system 72 No Threat Objects

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset suricata suricata
Integration ✅ Passing Dataset suricata suricata

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