F5 BIG-IP iControl REST API Bash Endpoint Command Execution via Proxy POST

Alerts on POST requests to the BIG-IP iControl REST /mgmt/tm/util/bash endpoint that can execute shell commands.

FreeReviewedSigma · Medium · v2

Category: proxy
Author: Nasreddine Bencherchali (Nextron Systems), Thurein Oo (SigmaHQ), DRL 1.1
Published: 2023-11-08
Updated: 2026-07-31

ATT&CK techniques

Initial Access

Recon
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags HTTP POST requests sent to the F5 BIG-IP iControl REST API bash endpoint (/mgmt/tm/util/bash) as observed by proxy telemetry. Attackers can use this endpoint to execute commands on the BIG-IP, making it a high-impact management-plane abuse scenario. Detection relies on capturing the request method and URI path suffix in the proxy logs.

Reporting behind it

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F5 BIG-IP iControl REST API Bash Endpoint Command Execution via Proxy POST

Pivot detection · T1190 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

f5-big-ip-icontrol-rest-api-bash-endpoint-command-execution-via-post-proxy-b59c98c6

title: F5 BIG-IP iControl REST API Bash Endpoint Command Execution via Proxy POST
id: aeb45920-4a21-4bb8-a2d2-4b7fdb13d75c
related:
  - id: 85254a62-22be-4239-b79c-2ec17e566c37
    type: similar
  - id: b59c98c6-95e8-4d65-93ee-f594dfb96b17
    type: derived
status: test
description: This rule flags HTTP POST requests sent to the F5 BIG-IP iControl REST API bash endpoint (/mgmt/tm/util/bash) as observed by proxy telemetry. Attackers can use this endpoint to execute commands on the BIG-IP, making it a high-impact management-plane abuse scenario. Detection relies on capturing the request method and URI path suffix in the proxy logs.
references:
  - https://f5-sdk.readthedocs.io/en/latest/apidoc/f5.bigip.tm.util.html#module-f5.bigip.tm.util.bash
  - https://community.f5.com/t5/technical-forum/icontrolrest-11-5-execute-bash-command/td-p/203029
  - https://community.f5.com/t5/technical-forum/running-bash-commands-via-rest-api/td-p/272516
  - https://github.com/SigmaHQ/sigma/blob/master/rules/web/proxy_generic/proxy_f5_tm_utility_bash_api_request.yml
author: Nasreddine Bencherchali (Nextron Systems), Thurein Oo, Huntrule Team
date: 2023-11-08
tags:
  - attack.initial-access
  - attack.t1190
logsource:
  category: proxy
detection:
  selection:
    cs-method: POST
    c-uri|endswith: /mgmt/tm/util/bash
  condition: selection
falsepositives:
  - Legitimate usage of the BIG IP REST API to execute command for administration purposes
level: medium
license: DRL-1.1

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