Microsoft Office - 'Composite Moniker Remote Code Execution

EDB-ID: 44263
Author: Rich Warren
Published: 2018-01-09
CVE: CVE-2017-8570
Type: Local
Platform: Windows
Aliases: N/A
Advisory/Source: Link
Tags: N/A
Vulnerable App: N/A

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]( 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 -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


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