Archives for 2005

I wrote yesterday about the security risks imposed by the SunnComm MediaMax copy protection technology that ships on some Sony CDs. (This is not to be confused with the XCP technology that Sony recalled.) MediaMax advocates may argue that it’s okay to impose these security risks on users, because MediaMax effectively prevents copying of music. Which raises an obvious question: How effective is MediaMax, really, in stopping copying?

The answer: Not very.

MediaMax reportedly can be defeated by the well-known trick of drawing a circle around the outer edge of the CD with a felt-tip pen, or covering the outer edge with tape.

MediaMax can be defeated by the well-known trick of holding down the Shift key while inserting the CD.

MediaMax can be defeated by the well-known trick of rebooting the computer after inserting the CD.

(These first three attacks don’t work if MediaMax is installed on the user’s computer. But MediaMax has released an uninstaller than anyone can use.)

MediaMax can be defeated by the well-known trick of not using a Windows PC. (Amusingly, Mac users are allowed to install MediaMax if they want to. To do this, the user has to browse the CD and double-click a MediaMax installer icon which might as well be labeled “Click here to make this CD less useful.” Users who are smart enough not to do this can access the music normally.)

MediaMax can be defeated by telling Sony you want to move the music into iTunes or an iPod. They will then send you instructions for defeating MediaMax by making an unprotected copy of the CD.

All this, and I haven’t even started talking about the details of how the MediaMax technology works and any detailed flaws in its operation.

The bottom line: MediaMax makes your computer less secure and your music less available for lawful use, while achieving very little against pirates.

Yesterday two lawsuits were filed against Sony, by the Texas Attorney General and the EFF. The Texas suit claims that Sony’s XCP technology violates the state’s spyware law. The EFF suit claims that two Sony technologies, XCP and MediaMax, both violate various state laws.

One interesting aspect of the EFF suit is its emphasis on MediaMax. Most of the other lawsuits have focused on Sony’s other copy protection technology, XCP. The EFF suit does talk about XCP, but only after getting through with MediaMax. Emphasizing MediaMax seems like a smart move – while Sony has issued an apology of sorts for XCP and has recalled XCP discs, the company is still stonewalling on MediaMax, even though MediaMax raises issues almost as serious as XCP.

As Alex wrote last week, MediaMax is spyware: it installs software without notice or consent; it phones home and sends back information without notice or consent; and it either doesn’t offer an uninstaller or makes the uninstaller difficult to get and use. MediaMax lacks the rootkit-like feature of XCP, but otherwise MediaMax shares all of the problems of XCP, including serious security problems with the uninstaller (mitigated by the difficulty of getting the uninstaller; see above).

But even if all these problems are fixed, the MediaMax software will still erode security, for reasons stemming from the basic design of the software.

For example, MediaMax requires administrator privileges in order to listen to a CD. You read that right: if you want to listen to a MediaMax CD, you must be logged in with enough privileges to manipulate any part of the system. The best practice is to log in to an ordinary (non-administrator) account, except when you need to do system maintenance. But with MediaMax, you must log in to a privileged account or you can’t listen to your CD. This is unnecessary and dangerous.

Some of the security risk of MediaMax comes from the fact that users are locked into the MediaMax music player application. The player app evades the measures designed to block access to the music; and of course the app can’t play non-MediaMax discs, so the user will have to use multiple music players. Having this extra code on the system, and having to run it, increases security risk. (And don’t tell me that music players don’t have security bugs – we saw two serious security security bugs in Sony music software last week.) Worse yet, if a security problem crops up in the MediaMax player app, the user can’t just switch to another player app. More code, plus less choice, equals more security risk.

Worse yet, one component of MediaMax, a system service called sbcphid, is loaded into memory and ready to run at all times, even when there is no disc in the CD drive and no music is being played. And it runs as a kernel process, meaning that it has access to all aspects of the system. This is another component that can only add to security risk; and again the user has no choice.

It’s important to recognize that these problems are caused not by any flaws in SunnComm and Sony’s execution of their copy protection plan, but from the nature of the plan itself. If you want to try to stop music copying on a PC, you’re going to have to resort to these kinds of methods. You’re going to have to force users to use extra software that they don’t want. You’re going to have to invoke administrator privileges more often. You’re going to have to keep more software loaded and running. You’re going to have to erode users’ ability to monitor, control, and secure their systems. Once you set off down the road of copy protection, this is where you’re going to end up.

I have good news and bad news about Sony’s other CD DRM technology, the SunnComm MediaMax system. (For those keeping score at home, Ed and I have written a lot recently about Sony’s XCP copy protection technology, but this post is about a separate system that Sony ships on other CDs.)

I wrote last weekend about SunnComm’s spyware-like behavior. Sony CDs protected with their technology automatically install several megabytes of files without any meaningful notice or consent, silently phone home every time you play a protected album, and fail to include any uninstall option.

Here’s the good news: As several readers have pointed out, SunnComm will provide a tool to uninstall their software if users pester them enough. Typically this requires at least two rounds of emails with the company’s support staff.

Now the bad news: It turns out that the web-based uninstaller SunnComm provides opens up a major security hole very similar to the one created by the web-based uninstaller for Sony’s other DRM, XCP, that we announced a few days ago. I have verified that it is possible for a malicious web site to use the SunnComm hole to take control of PCs where the uninstaller has been used. In fact, the the SunnComm problem is easier to exploit than the XCP uninstaller flaw.

To be clear, the SunnComm security flaw does not apply to the software that ships on CDs, but only to the uninstaller that SunnComm distributes separately for removing the CD software. So if you haven’t used the uninstaller, you’re not vulnerable to this flaw and you don’t need to do anything.

If you visit the SunnComm uninstaller web page, you are prompted to accept a small software component—an ActiveX control called AxWebRemoveCtrl created by SunnComm. This control has a design flaw that allows any web site to cause it to download and execute code from an arbitrary URL. If you’ve used the SunnComm uninstaller, the vulnerable AxWebRemoveCtrl component is still on your computer, and if you later visit an evil web site, the site can use the flawed control to silently download, install, and run any software code it likes on your computer. The evil site could use this ability to cause severe damage, such as adding your PC to a botnet or erasing your hard disk.

You can tell whether the vulnerable control is installed on your computer by using our AxWebRemoveCtrl detector.

We have created a tool that will disable the control and/or block it from being installed. To apply our tool, download this file to a temporary location, then double click on the file’s icon in Windows. (Windows may ask you to confirm that you wish to add the information in the file to the system registry–choose “Yes.”) After the tool has been applied, you may delete the file you downloaded. The tool will take effect as soon as you close and restart Internet Explorer. We recommend that anyone who has used the SunnComm uninstaller run our tool as soon as possible.

Unfortunately, if you use our tool to block the control, you won’t be able to use SunnComm’s current uninstaller to remove their software. It’s up to them to replace the flawed uninstaller with a safe one as soon as possible, and to contact those who have already used the vulnerable uninstaller with instructions for closing the hole.

UPDATE (Nov. 18): We are currently helping SunnComm test a new version of the uninstaller.

Jeff Dwoskin and Alex Halderman have developed a simple tool that can immunize a Windows system against the dangerous CodeSupport ActiveX control that we have written about over the past few days. The immunization tool should disable CodeSupport if it is already on your system, and it should prevent any future reinstallation or reactivation of CodeSupport.

You can test whether the vulnerable CodeSupport component is installed on your system using our CodeSupport detector web page. If you are infected, we strongly recommend that you run our immunization tool. Even if you are not infected, you can apply our patch to prevent the flawed control from being installed in the future.

To install the tool, download this file to a temporary location, then double click on the file’s icon in Windows. (Windows may ask you to confirm that you wish to add the information in the file to the system registry–choose “Yes.”) After the tool has been applied, you may delete the file. The tool will take effect as soon as you close and restart Internet Explorer.

The tool works by putting an entry into the Windows registry that tells Internet Explorer not to activate any ActiveX control that uses the unique identifier (or “classid”) associated with CodeSupport. This registry area is described in a Microsoft KnowledgeBase article.

Sony has modified their uninstaller sequence so that users who want to start the uninstallation process will not download CodeSupport. That’s good. But unfortunately the CodeSupport component is still up on the company’s web site, so users who were already partway through the uninstall process might still download CodeSupport. That’s not good; but it’s easy to fix. Let’s hope Sony fixes it.

Meanwhile, the company is reportedly working to develop a safe uninstaller. We’ll let you know when they release an uninstaller, and we’ll tell you what we think of it.