false positives should be limited to as this is strict to active exploitation. reduce noise by filtering to f5 devices with tmui enabled or filter data as needed.

Techniques

Sample rules

F5 TMUI Authentication Bypass

source: splunk
technicques:

Description

The following analytic detects attempts to exploit the CVE-2023-46747 vulnerability, an authentication bypass flaw in F5 BIG-IP’s Configuration utility (TMUI). It identifies this activity by monitoring for specific URI paths such as “/mgmt/tm/auth/user/” with the PATCH method and a 200 status code. This behavior is significant for a SOC as it indicates potential unauthorized access attempts, leading to remote code execution. If confirmed malicious, an attacker could gain unauthorized access, execute arbitrary code, steal data, disrupt systems, or conduct further malicious activities within the network.

Detection logic


| tstats count min(_time) as firstTime max(_time) as lastTime from datamodel=Web where Web.url IN ("*/mgmt/tm/auth/user/*") Web.http_method=PATCH Web.status=200 by Web.http_user_agent, Web.status Web.http_method, Web.url, Web.url_length, Web.src, Web.dest, sourcetype 
| `drop_dm_object_name("Web")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)`
| `f5_tmui_authentication_bypass_filter`