Web Spring Cloud Function FunctionRouter
The following analytic identifies activity related to the web application Spring Cloud Function that was recently idenfied as vulnerable. This is CVE-2022-22963. Multiple proof of concept code was released. The URI that is hit includes
functionrouter. The specifics of the exploit include a status of 500. In this query we did not include it, but for filtering you can add Web.status=500. The exploit data itself (based on all the POCs) is located in the form_data field. This field will include all class.modules being called.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Web
- Last Updated: 2022-04-05
- Author: Michael Haag, Splunk
- ID: 89dddbad-369a-4f8a-ace2-2439218735bc
Kill Chain Phase
- CIS 13
|CVE-2022-22963||In Spring Cloud Function versions 3.1.6, 3.2.2 and older unsupported versions, when using routing functionality it is possible for a user to provide a specially crafted SpEL as a routing-expression that may result in remote code execution and access to local resources.||7.5|
1 2 3 4 5 6 | 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 | `drop_dm_object_name("Web")` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `web_spring_cloud_function_functionrouter_filter`
The SPL above uses the following Macros:
web_spring_cloud_function_functionrouter_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this search you need to be ingesting information on Web traffic that include fields relavent for traffic into the
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
|42.0||70||60||A suspicious URL has been requested against $dest$ by $src$, related to a vulnerability in Spring Cloud.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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 | version: 1