Missing Trust Validation in Visual Studio’s VSIX Installer

Posted by Ostovary, Daniel on Aug 29

Hi,

we have recently discovered a vulnerability in the VSIX Installer of Visual Studio. More specifically, the
vulnerability existed in the validation of VSIX package signatures. This vulnerability allowed attackers

* to ‘revive’ expired code-signing certificates for VSIX package signatures and

* to maliciously modify timestamps when intercepting timestamp requests for VSIX package signatures.

For more details see…