F5 TMUI Authentication Bypass

name: F5 TMUI Authentication Bypass
id: 88bf127c-613e-4579-99e4-c4d4b02f3840
version: 7
date: '2026-03-10'
author: Michael Haag, Splunk
status: production
type: TTP
data_source:
    - Suricata
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.
search: |-
    | 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`
how_to_implement: To successfully implement this search you need to be ingesting information on Web traffic that include fields relevant for traffic into the `Web` datamodel.
known_false_positives: 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.
references:
    - https://www.praetorian.com/blog/refresh-compromising-f5-big-ip-with-request-smuggling-cve-2023-46747/
    - https://github.com/projectdiscovery/nuclei-templates/blob/3b0bb71bd627c6c3139e1d06c866f8402aa228ae/http/cves/2023/CVE-2023-46747.yaml
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: Potential CVE-2023-46747 F5 TMUI Authentication Bypass may be occurring against $dest$ from $src$.
    risk_objects:
        - field: dest
          type: system
          score: 50
    threat_objects:
        - field: src
          type: ip_address
tags:
    analytic_story:
        - F5 Authentication Bypass with TMUI
    asset_type: Network
    atomic_guid: []
    cve:
        - CVE-2023-46747
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1190/f5/f5_tmui.log
          source: not_applicable
          sourcetype: suricata