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The following analytic detects attempts to exploit the F5 BIG-IP iControl REST API vulnerability (CVE-2022-1388) for unauthenticated remote code execution. It identifies suspicious URI paths and POST HTTP methods, along with specific request headers containing potential commands in the utilcmdargs field and a random base64 encoded value in the X-F5-Auth-Token field. This activity is significant as it targets a critical vulnerability that can allow attackers to execute arbitrary commands on the affected system. If confirmed malicious, this could lead to full system compromise and unauthorized access to sensitive data.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Web
  • Last Updated: 2024-05-28
  • Author: Michael Haag, Splunk
  • ID: bb1c2c30-107a-4e56-a4b9-1f7022867bfe




ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
T1133 External Remote Services Persistence, Initial Access
Kill Chain Phase
  • Delivery
  • Installation
  • DE.CM
  • CIS 13
| 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`


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


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.


Test Dataset

Replay any dataset to Splunk Enterprise by using our tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 2