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Description

The following analytic identifies a recent unauthenticated remote code execution vulnerablity against the F5 BIG-IP iControl REST API. The analytic identifies the URI path found in the POCs and the HTTP Method of POST. In addition, the request header will have the commands that may be executed in fields utilcmdargs and the auth field of X-F5-Auth-Token, which may have a random base64 encoded value.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Web
  • Last Updated: 2022-05-10
  • Author: Michael Haag, Splunk
  • ID: bb1c2c30-107a-4e56-a4b9-1f7022867bfe

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
T1133 External Remote Services Persistence, Initial Access
Kill Chain Phase
  • Delivery
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 13
CVE
ID Summary CVSS
CVE-2022-1388 On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, 13.1.x versions prior to 13.1.5, and all 12.1.x and 11.6.x versions, undisclosed requests may bypass iControl REST authentication. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated 7.5 


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| tstats count from datamodel=Web where Web.url="*/mgmt/tm/util/bash*" Web.http_method="POST" by Web.http_user_agent Web.http_method, Web.url,Web.url_length Web.src, Web.dest 
| `drop_dm_object_name("Web")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `f5_big_ip_icontrol_rest_vulnerability_cve_2022_1388_filter`

Macros

The SPL above uses the following Macros:

:information_source: f5_big-ip_icontrol_rest_vulnerability_cve-2022-1388_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • Web.http_method
  • Web.url
  • Web.url_length
  • Web.src
  • Web.dest
  • Web.http_user_agent

How To Implement

To successfully implement this search, you need to be ingesting web or proxy logs, or ensure it is being filled by a proxy like device, into the Web Datamodel. For additional filtering, allow list private IP space or restrict by known good.

Known False Positives

False positives may be present if the activity is blocked or was not successful. Filter known vulnerablity scanners. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
70.0 100 70 An attempt to exploit CVE-2022-1388 against an F5 appliance $dest$ has occurred.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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

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