web_spring_cloud_function_functionrouter.yml

name: Web Spring Cloud Function FunctionRouter
id: 89dddbad-369a-4f8a-ace2-2439218735bc
version: 1
date: '2022-04-05'
author: Michael Haag, Splunk
status: production
type: TTP
description: 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.
data_source: []
search: '| 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`'
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 `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.
references:
- https://github.com/rapid7/metasploit-framework/pull/16395
- https://github.com/hktalent/spring-spel-0day-poc
tags:
  analytic_story:
  - Spring4Shell CVE-2022-22965
  asset_type: Web Server
  confidence: 60
  cve:
  - CVE-2022-22963
  impact: 70
  message: A suspicious URL has been requested against $dest$ by $src$, related to
    a vulnerability in Spring Cloud.
  mitre_attack_id:
  - T1190
  - T1133
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: src
    type: IP Address
    role:
    - Attacker
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Web.http_method
  - Web.url
  - Web.url_length
  - Web.src
  - Web.dest
  - Web.http_user_agent
  risk_score: 42
  security_domain: network
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1190/spring4shell/all_functionrouter_http_streams.log
    source: stream:http
    sourcetype: stream:http