ID | Technique | Tactic |
---|---|---|
T1190 | Exploit Public-Facing Application | Initial Access |
T1133 | External Remote Services | Initial Access |
Detection: Web Spring Cloud Function FunctionRouter
Description
The following analytic identifies HTTP POST requests to the Spring Cloud Function endpoint containing "functionRouter" in the URL. It leverages the Web data model to detect these requests based on specific fields such as http_method, url, and http_user_agent. This activity is significant because it targets CVE-2022-22963, a known vulnerability in Spring Cloud Function, which has multiple proof-of-concept exploits available. If confirmed malicious, this activity could allow attackers to execute arbitrary code, potentially leading to unauthorized access, data exfiltration, or further compromise of the affected system.
Search
1
2| tstats count from datamodel=Web where Web.http_method IN ("POST") Web.url="*/functionRouter*" by Web.http_user_agent Web.http_method, Web.url,Web.url_length Web.src, Web.dest Web.status sourcetype
3| `drop_dm_object_name("Web")`
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)`
6| `web_spring_cloud_function_functionrouter_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Splunk Stream HTTP | Splunk | 'stream:http' |
'stream:http' |
N/A |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
web_spring_cloud_function_functionrouter_filter | search * |
web_spring_cloud_function_functionrouter_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 successfully implement this search you need to be ingesting information on Web traffic that include fields relavent for traffic into the Web
datamodel.
Known False Positives
False positives may be present with legitimate applications. Attempt to filter by dest IP or use Asset groups to restrict to servers.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A suspicious URL has been requested against $dest$ by $src$, related to a vulnerability in Spring Cloud. | 42 | 70 | 60 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | stream:http |
stream:http |
Integration | ✅ Passing | Dataset | stream:http |
stream:http |
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