WinRAR at Risk of Huge New Zero Day Vulnerability

WinRAR has a base of some 500 million users worldwide, those same users might want to take a look at a new Zero Day Vulnerability which has been detected within the newest version of the software. According to Mohammad Reza Espargham, who is a security researcher at Vulnerability – Lab, the stable version of WinRAR 5.21 for Windows computers is vulnerable to a “remote code execution (RCE) flaw”. Let’s digest this flaw by breaking it down and having a closer look.

The vulnerability works by being implemented by an attacker with the aim of inserting a malicious HTML code inside the “Text to display in SFX window” section when the user is creating a new SFX file. Below is a video which conveys a test that proves the existence of this flaw, albeit in a controlled environment.

The annoying flaw with SFX files is they will start auto functioning the moment a user clicks on them, therefore, consumers cannot identify or verify if the compressed .exe file is a genuine WinRAR module or a malicious one. As of writing, there is yet to be a patch released for this flaw and Windows users are advised to refrain from clicking on any files from unknown sources. If you wish to protect yourself further, then by all means use an alternative archiving product or use strict authentication methods to secure your system.

The knock on effect of any exploit can be harmful to users, especially when a product has a consumer base which is substantial in size.

Thank you thehackernews for providing us with this information.

Image courtesy of tecnoandroid