CVE-2020-6492 a use-after-free Vulnerability Fixed for Google Chrome Version 85

CVE-2020-6492 a use-after-free vulnerability that exists in ANGLE, a compatibility layer between OpenGL and Direct3D that Chrome uses on Windows systems [2]. In normal operations in the program it would allocate the memory and store it. A pointer is then created to access the memory. From there the memory is deleted making the pointer invalid for use, which then is passed back to the memory manager as a variable point. In the use-after-free vulnerability after memory is deleted instead of the pointer being invalid it continues to use the pointer therefore allowing the attacker to access that free memory which may contain content that was intended to be deleted. In the code of the ANGLE function there is a line called “State::syncTextures” with the responsibility to check if the texture has any DirtyBits. During this process there is a crash within the code when the texture is trying to syncState leading to the “Texture::syncState” function. This crash is caused from the use-after-free attempt that is being made to access memory after “it has been freed” in between the functions of “drawArraysInstanced” and “SafeDelete” built within the code giving the attacker the ability to exploit and create arbitrary code [3].