Microsoft Office Composite Moniker Remote Code Execution

2018.03.09
Credit: Rich Warren
Risk: High
Local: No
Remote: Yes
CWE: N/A

## What? This repo contains a Proof of Concept exploit for CVE-2017-8570, a.k.a the "Composite Moniker" vulnerability. This demonstrates using the Packager.dll trick to drop an sct file into the %TEMP% directory, and then execute it using the primitive that the vulnerability provides. ## Why? A few reasons. 1. I wanted to see if it was possible to use the [Packager.dll file-dropping trick](https://securingtomorrow.mcafee.com/mcafee-labs/dropping-files-temp-folder-raises-security-concerns/) to exploit this vulnerability. 2. As far as I'm aware, all other public exploits for CVE-2017-8570 are actually exploiting the "Script Moniker" variant of CVE-2017-0199 and are not actually composite moniker exploits. 3. Raise awareness of exploitation techniques used in the wild, and help defenders to detect exploitation attempts. ## How to run Simply run the script, providing an Sct file to execute, and an output name for your RTF file: python packager_composite_moniker.py -s calc.sct -o example.rtf [+] RTF file written to: example.rtf ## Detection I have included a Yara rule to detect attempts to exploit this vulnerability via RTF. ## References - https://justhaifei1.blogspot.co.uk/2017/07/bypassing-microsofts-cve-2017-0199-patch.html - https://securingtomorrow.mcafee.com/mcafee-labs/dropping-files-temp-folder-raises-security-concerns/ - https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8570

References:

https://justhaifei1.blogspot.co.uk/2017/07/bypassing-microsofts-cve-2017-0199-patch.html
https://securingtomorrow.mcafee.com/mcafee-labs/dropping-files-temp-folder-raises-security-concerns/
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8570


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