Security

The EFF's report on trusted computing

The Electronic Frontier Foundation has released, to a fair amount of fanfare, its report on trusted computing. The report's author (Seth Schoen) has concluded that, while trusted computing architectures offer a number of security benefits, there are also potential problems that need to be addressed.

The report mentions four different technologies that make up current trusted computing efforts:

• Memory curtaining. Modern operating systems already go to considerable lengths to keep one process from being able to mess with another process's memory. Memory curtaining takes things further by improving memory isolation support in the hardware, so that even the kernel cannot modify one process's memory while working on behalf of another process.

• Secure I/O is the creation of a data path from the keyboard (or other input devices) to the application, and from the application to the screen which cannot be seen or modified by other processes. It is an attempt to stop software keystroke loggers, screen readers, and other eavesdropping tools.

• Sealed storage works by hiding encryption keys within the system hardware, so that encrypted data cannot be read anywhere else.

• Remote attestion is a hardware-supported mechanism for ensuring that the software running on a system has not been modified. The technology allows the generation of certificates that can allow a remote application (a web server, say) to be sure of the software it is talking to.

The report acknowledges that all of these technologies can help to improve the security of computer systems. With a trusted computing architecture in place, a worm which is able to exploit a hole in one program will find its ability to do anything interesting on the system much reduced. The EFF does not have any real problem with most of the technologies discussed.

That is not true, however, for remote attestation:

A few cases where the remote attestation feature could backfire on users are mentioned. One is web servers which refuse to talk to anything other than the One Chosen Browser. There are sites which do that now, but most modern browsers are capable of masquerading as something else, so these techniques are not effective. Remote attestion would change that. Other examples include software interoperability (i.e. eliminating Samba forevermore), forced upgrades, and forced use of digital rights management schemes.

As a solution, the EFF suggests an "owner override" feature. The owner of a system could, while physically present at the machine, force it to produce an attestation for software that the owner has modified or replaced, making it look like something else. This feature would solve the problem for suitably capable users. It is hard to imagine users developing a widespread ability to safely perform overrides, however.

The real conclusion to be taken from this report is that the owners and users of computers need to maintain control over their machines. When your own computer treats you like an attacker, it has ceased to be truly yours, and it becomes a tool for controlling your behavior. Free software users have understood this point for years, of course. We have built a system that allows us to stay in control. But we need to be careful that the hardware platforms of the future do not take that control away from us.

Comments (10 posted)

cfengine: stack overflow

Package(s):	cfengine	CVE #(s):
Created:	October 8, 2003	Updated:	October 8, 2003
Description:	Versions of cfengine prior to 2.0.8 contain a stack overflow in the network I/O code which can be exploited remotely. See this advisory for details.
Alerts:	Gentoo 200310-2 cfengine 2003-10-04

Comments (none posted)

Analysis of the MediaMax CD3 copy-prevention system

John A. Halderman has analyzed the "CD3" copy protection system for audio CDs and posted his results. It seems that this technology works by loading a special driver via the Windows autorun feature; the driver interferes with read operations, thus thwarting copy attempts. But only if the driver is actually loaded. "MediaMax's protections are ineffective because the driver program can easily be disabled or, depending on the system configuration, it might never be installed to begin with. As a result, audio content is vulnerable to copying in virtually 100% of deployed systems.... Computers running Linux or Mac OS 9 can't run the MediaMax software at all, so they can always copy the recording." Sometimes the lack of Linux support is a good thing.

Comments (21 posted)

LinuxSecurity.com newsletters

This week's Linux Advisory Watch and Linux Security Week newsletters from LinuxSecurity.com are available.

Comments (none posted)

EICAR 2004

The 13th Annual EICAR Conference will be held at the Hilton Luxembourg in Luxemburg City from May 1 to 4, 2004. "Participants can expect a variety of academic and leading edge technical presentations from around the world, with an emphasis not only on technical aspects of IT-security, but also the legal and social issues rapidly becoming the new thorn in everyone's collective side." The call for papers has gone out, with a submission deadline of January 15.

Full Story (comments: none)