SigmaHQ/rules/web/web_citrix_cve_2019_19781_exploit.yml

title: Citrix Netscaler Attack CVE-2019-19781
description: Detects CVE-2019-19781 exploitation attempt against Citrix Netscaler, Application Delivery Controller and Citrix Gateway Attack
id: ac5a6409-8c89-44c2-8d64-668c29a2d756
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/x1sec.github.io/blob/master/CVE-2019-19781-DFIR.md
author: Arnim Rupp, Florian Roth
status: experimental
date: 2020/01/02
modified: 2020/03/14
logsource:
    category: webserver
    description: '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:
        c-uri: 
            - '*/../vpns/*'
            - '*/vpns/cfg/smb.conf'
            - '*/vpns/portal/scripts/*.pl*'
    condition: selection
fields:
    - client_ip
    - vhost
    - url
    - response
falsepositives:
    - Unknown
level: critical
rule: updated netscaler rule 2020-01-07 13:42:16 +00:00			`title: Citrix Netscaler Attack CVE-2019-19781`
			`description: Detects CVE-2019-19781 exploitation attempt against Citrix Netscaler, Application Delivery Controller and Citrix Gateway Attack`
add rule for Citrix Netscaler CVE-2019-19781 2020-01-03 00:48:29 +00:00			`id: ac5a6409-8c89-44c2-8d64-668c29a2d756`
add rule for Citrix Netscaler CVE-2019-19781 2020-01-02 23:34:52 +00:00			`references:`
			`- https://support.citrix.com/article/CTX267679`
			`- https://support.citrix.com/article/CTX267027`
rule: updated netscaler rule 2020-01-07 13:42:16 +00:00			`- https://isc.sans.edu/diary/25686`
rule: changes at Shitrix rule 2020-01-13 19:13:32 +00:00			`- https://twitter.com/mpgn_x64/status/1216787131210829826`
complete_cve_2019-19781 2020-01-15 20:59:33 +00:00			`- https://github.com/x1sec/x1sec.github.io/blob/master/CVE-2019-19781-DFIR.md`
rule: updated netscaler rule 2020-01-07 13:42:16 +00:00			`author: Arnim Rupp, Florian Roth`
add rule for Citrix Netscaler CVE-2019-19781 2020-01-02 23:34:52 +00:00			`status: experimental`
			`date: 2020/01/02`
use the taxonomy which states to use `c-uri` instead of `c-uri-path` 2020-03-14 19:02:06 +00:00			`modified: 2020/03/14`
add rule for Citrix Netscaler CVE-2019-19781 2020-01-02 23:34:52 +00:00			`logsource:`
			`category: webserver`
complete_cve_2019-19781 2020-01-15 20:59:33 +00:00			`description: '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.'`
add rule for Citrix Netscaler CVE-2019-19781 2020-01-02 23:34:52 +00:00			`detection:`
			`selection:`
use the taxonomy which states to use `c-uri` instead of `c-uri-path` 2020-03-14 19:02:06 +00:00			`c-uri:`
rule: updated netscaler rule 2020-01-07 13:42:16 +00:00			`- '/../vpns/'`
			`- '*/vpns/cfg/smb.conf'`
complete_cve_2019-19781 2020-01-15 20:59:33 +00:00			`- '/vpns/portal/scripts/.pl*'`
add rule for Citrix Netscaler CVE-2019-19781 2020-01-02 23:34:52 +00:00			`condition: selection`
			`fields:`
			`- client_ip`
			`- vhost`
			`- url`
			`- response`
			`falsepositives:`
			`- Unknown`
			`level: critical`
fix: shortened path in Citrix Netscaler rule 2020-01-07 12:00:28 +00:00