topic Re: Is CVE-2021-4034 covered by Cortex XDR? in Cortex XDR Discussions

Is CVE-2021-4034 covered by Cortex XDR?

fhu_omi — Wed, 26 Jan 2022 15:35:35 GMT

Hi,

does anyone know if the vulnerability CVE-2021-4034 is covered by Cortex XDR Prevent or Pro?

Source: https://blog.qualys.com/vulnerabilities-threat-research/2022/01/25/pwnkit-local-privilege-escalation-vulnerability-discovered-in-polkits-pkexec-cve-2021-4034

Kind regards

Re: Is CVE-2021-4034 covered by Cortex XDR?

etugriceri — Wed, 26 Jan 2022 16:34:11 GMT

Dear fhu_omi

There is no content update specifically for CVE-2021-4034 yet but this does not mean that you'll be unprotected. Cortex XDR focuses TTP's and unknowns and You'll be protected by BTP module.

Re: Is CVE-2021-4034 covered by Cortex XDR?

fhu_omi — Mon, 31 Jan 2022 07:30:33 GMT

Dear @etugriceri

I will test it, then we will see if there existing modules will cover this pointer vulnerability. There is a test program out now: https://pythonrepo.com/repo/kimusan-pkwner

Re: Is CVE-2021-4034 covered by Cortex XDR?

Luc_Desaulniers — Wed, 02 Feb 2022 17:23:41 GMT

Hello @fhu_omi, did you get a chance to run some tests?

I ran a test on a test environment with XDR pro enabled and the exploit was allowed to execute without tripping anything on Cortex side initially. I did get a wildfire post detection a few hours later.

I'd like to hear others feedback for this one.

Thanks

Re: Is CVE-2021-4034 covered by Cortex XDR?

P.Jacob — Thu, 03 Feb 2022 21:25:52 GMT

what version and content release is your asset on?

Re: Is CVE-2021-4034 covered by Cortex XDR?

etugriceri — Mon, 07 Feb 2022 16:18:46 GMT

Hi @fhu_omi

did some test on this and I'm sharing a couple of sample below. You can play with them better detection or prevention. For the prevention, You need to create BIOC rule and add to Linux restriction profile. I'm sharing for demonstration purposes, might be intrusive and might need find tuning on it before using production. But the point is, even if PANW not shared BIOC via content update, still you can write your own prevention rule.

For detection
preset = xdr_process
| filter action_process_image_command_line contains "GCONV" and action_process_image_name in ("sh","bash","zsh") and actor_process_image_name = "pkexec" and agent_os_type = ENUM.AGENT_OS_LINUX

preset = xdr_process
| filter action_process_image_command_line contains "GCONV" and action_process_image_name in ("sh","bash","zsh") and agent_os_type = ENUM.AGENT_OS_LINUX

for Prevention
Process [ action type = execution AND target process cmd = *GCONV* ] AND Host [ host os = linux ]

Process [ action type = execution AND target process cmd = sh*GCONV*sh , bash*GCONV*bash ] AND Host [ host os = linux ]

Process [ action type = execution AND target process name = sh , bash , zsh AND target process cmd = *GCONV* ] AND Host [ host os = linux ]

(three different sample)