As reported yesterday by Infosecurity, Adobe's updates this week were hit by misrouting of Apple Mac users to Windows updates, and the ongoing availability of Adobe Reader 9.3.0, despite the software having two known security vulnerabilities.
Now it seems that the Adobe Download Manager itself is flawed, with a bug allegedly allowing hackers to remotely install malicious files on user's PCs.
The bug stems from the fact that the Download Manager is an ActiveX script that is widely used to install a variety of software and patches across the Adobe internet empire.
According to Israeli security researcher, Aviv Raff, who has identified many other software vulnerabilities, the flaw allows a third-party application to be called and installed on the remote machine, provided the user clicks on a link.
In a blog posting, Raff said: "We all have heard about the recent zero-day vulnerabilities in several widely deployed Adobe products."
"Adobe's response to some of them has been at times outrageous.... Recently, I found a design flaw on Adobe's website, which allows the abuse of the Adobe Download Manager to force the automatic installation of Adobe products, as well as other software products (e.g., Google Toolbar)", he said.
"Instead of admitting that this design flaw is indeed a problem which can be abused by malicious attackers, Adobe decided to downplay this issue", he added.
According to Raff, when ZDNet Zero Day blogger Ryan Naraine reported Aviv's discovery to Adobe, the company sent this response:
A few important points:
The Adobe Download Manager is intended for one-time use. The Adobe Download Manager is designed to remove itself from the computer after use at the next restart. The user can also remove the Adobe Download Manager prior to this using Add/Remove Programs.
The Adobe Download Manager can only be used to download the latest version of software hosted on Adobe.com.
The Adobe Download Manager presents a very large user dialog box when downloading software.
Raff alleges that Adobe has missed the point: "This is not a far-fetched 'what if' – an attacker can force you to automatically download and install the vulnerable Adobe product, and then exploit the zero-day vulnerability in that product", he said.
"Until Adobe decides to fix this vulnerability, I'm going to withhold the technical details of how to exploit this vulnerability. But, I can say that Adobe's claim in regards to Adobe Download Manager use of SSL in downloading the software is simply not true", he added.