Making a PoC for CVE-2020-0668

Making a PoC for CVE-2020-0668

Recently Clément Labro released a blog post about an arbitrary file move vulnerability he discovered. This was CVE-2020-0668 which involved abusing Service Tracing to cause an arbitrary file move with the help of symlinks.

 

I confirmed the vulnerability using the Google Project Zero symboliclink-testing-tools but wanted to create a standalone executable, that could be easily shipped to a target machine to exploit the CVE. C# seemed like an appropriate language as I could leverage the NtApiDotNet package which had done all the hard work for me.
​
Writing the code was as simple as following the instructions in the blog post and making sure I understand the mount point  and symbolic link trickery. Luckily this has been described by James Forshare in a number of blog posts, and implemented in his API methods NtFile.CreateMountPoint and NtSymbolicLink.Create. The complete proof of concept code can be found on GitHub here.

More Blogs

View All Blogs
May 31, 2021

Upgrading from AppLocker to Windows Defender Application Control (WDAC)

Windows Defender Application Control (WDAC), formerly known as Device Guard, is a Microsoft Windows secure feature that restricts executable code, including scripts run by enlightened Windows script hosts, to those that conform to the device code integrity policy. WDAC prevents the execution, loading and running of unwanted or malicious code, drivers and scripts. WDAC also… Continue reading Upgrading from AppLocker to Windows Defender Application Control (WDAC)

Read More
cyber security companies | penetration testing | managed security service provider | cyber security consultant
June 22, 2021

Bypassing LSA Protection (aka Protected Process Light) without Mimikatz on Windows 10

Starting with Windows 8.1 (and Server 2012 R2) Microsoft introduced a feature termed LSA Protection. This feature is based on the Protected Process Light (PPL) technology which is a defense-in-depth security feature that is designed to “prevent non-administrative non-PPL processes from accessing or tampering with code and data in a PPL process via open process… Continue reading Bypassing LSA Protection (aka Protected Process Light) without Mimikatz on Windows 10

Read More
cyber security companies | penetration testing | managed security service provider | cyber security consultant
June 7, 2020

Using Zeek to detect exploitation of Citrix CVE-2019-19781

Using the tool Zeek, formally known as bro, is a high-level packet analysis program. It originally began development in the 1990s and has a long history. It does not directly intercept or modify traffic, rather it passively observes it and creates high-level network logs. It can be used in conjunction with a SIEM to allow… Continue reading Using Zeek to detect exploitation of Citrix CVE-2019-19781

Read More