splunk_digital_certificates_lack_of_encryption.yml

name: Splunk Digital Certificates Lack of Encryption
id: 386a7ebc-737b-48cf-9ca8-5405459ed508
version: 1
date: '2022-05-26'
author: Lou Stella, Splunk
status: production
type: Anomaly
description: On June 14th, 2022, Splunk released a security advisory relating to the
  authentication that happens between Universal Forwarders and Deployment Servers.
  In some circumstances, an unauthenticated client can download forwarder bundles
  from the Deployment Server. In other circumstances, a client may be allowed to publish
  a forwarder bundle to other clients, which may allow for arbitrary code execution.
  The fixes for these require upgrading to at least Splunk 9.0 on the forwarder as
  well. This is a great opportunity to configure TLS across the environment. This
  search looks for forwarders that are not using TLS and adds risk to those entities.
data_source: 
- Splunk
search: '`splunkd` group="tcpin_connections" ssl="false" | stats values(sourceIp)
  latest(fwdType) latest(version) by hostname | `splunk_digital_certificates_lack_of_encryption_filter`'
how_to_implement: This anomaly search looks for forwarder connections that are not
  currently using TLS. It then presents the source IP, the type of forwarder, and
  the version of the forwarder. You can also remove the "ssl=false" argument from
  the initial stanza in order to get a full list of all your forwarders that are sending
  data, and the version of Splunk software they are running, for audit purposes. Splunk
  SOAR customers can find a SOAR workbook that walks an analyst through the process
  of running these hunting searches in the references list of this detection. In order
  to use this workbook, a user will need to run a curl command to post the file to
  their SOAR instance such as "curl -u username:password https://soar.instance.name/rest/rest/workbook_template
  -d @splunk_psa_0622.json". A user should then create an empty container or case,
  attach the workbook, and begin working through the tasks.
known_false_positives: None at this time
references:
- https://www.splunk.com/en_us/product-security/announcements/svd-2022-0607.html
- https://www.splunk.com/en_us/product-security/announcements/svd-2022-0601.html
- https://www.github.com/splunk/security_content/blob/develop/workbooks/splunk_psa_0622.json
tags:
  analytic_story:
  - Splunk Vulnerabilities
  asset_type: Endpoint
  confidence: 80
  cve:
  - CVE-2022-32151
  impact: 25
  message: $hostname$ is not using TLS when forwarding data
  mitre_attack_id:
  - T1587.003
  observable:
  - name: hostname
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - group
  - ssl
  - sourceIp
  - fwdType
  - version
  - hostname
  risk_score: 20
  security_domain: threat
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1587.003/splunk_fwder/splunkd.log
    source: /opt/splunk/var/log/splunk/metrics.log
    sourcetype: splunkd
    update_timestamp: false
    custom_index: _internal