title: Fortinet CVE-2021-22123 Exploitation
description: Detects CVE-2021-22123 exploitation attempt against Fortinet WAFs
id: f425637f-891c-4191-a6c4-3bb1b70513b4
status: experimental
references:
    - https://www.rapid7.com/blog/post/2021/08/17/fortinet-fortiweb-os-command-injection
author: Bhabesh Raj, Florian Roth
date: 2021/08/19
tags:
    - attack.initial_access
    - attack.t1190
logsource:
    category: webserver
detection:
    selection:
        c-uri|contains: 
            - '/api/v2.0/user/remoteserver.saml'
        cs-method:
            - POST
    filter1:
        cs-referer|contains: '/root/user/remote-user/saml-user/'
    filter2:
        cs-referer:
            - null
    condition: selection and not filter1 and not filter2
fields:
    - client_ip
    - url
    - response
falsepositives:
    - Unknown
level: critical