title: Citrix Netscaler Attack CVE-2019-19781
id: ac5a6409-8c89-44c2-8d64-668c29a2d756
status: test
description: Detects CVE-2019-19781 exploitation attempt against Citrix Netscaler, Application Delivery Controller and Citrix Gateway Attack
references:
    - https://support.citrix.com/article/CTX267679
    - https://support.citrix.com/article/CTX267027
    - https://isc.sans.edu/diary/25686
    - https://twitter.com/mpgn_x64/status/1216787131210829826
    - https://github.com/x1sec/CVE-2019-19781/blob/25f7ab97275b2d41800bb3414dac8ca3a78af7e5/CVE-2019-19781-DFIR.md
author: Arnim Rupp, Florian Roth
date: 2020-01-02
modified: 2023-01-02
tags:
    - attack.initial-access
    - attack.t1190
    - cve.2019-19781
    - detection.emerging-threats
logsource:
    category: webserver
    definition: 'Make sure that your Netscaler appliance logs all kinds of attacks (test with http://your-citrix-gw.net/robots.txt). The directory traversal with ../ might not be needed on certain cloud instances or for authenticated users, so we also check for direct paths. All scripts in portal/scripts are exploitable except logout.pl.'
detection:
    selection_cs:
        - cs-uri-query|contains: '/../vpns/'
        - cs-uri-query|endswith: '/vpns/cfg/smb.conf'
    selection_csall:
        cs-uri-query|contains|all:
            - '/vpns/portal/scripts/'
            - '.pl'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: critical