Shellshock: a very bad vulnerability in a very common *nix tool

Linux and other flavours of the Unix operating system (aka *nix) run about half of the world’s web servers. Increasingly, *nix also runs on Internet-enabled hardware, including routers and modems. A huge proportion of these systems also have BASH configured as the default command interpreter (aka shell).

A serious vulnerability in BASH was recently discovered. The full extent of the danger related to this vulnerability has yet to be determined, because the bug opens up a world of possible exploits. As an example, the bug can be demonstrated by issuing a specially-crafted request to a vulnerable web server that results in that server pinging another computer.

Patches that address the vulnerability (at least partially) became available almost immediately for most Linux flavours. Apple’s OS X has yet to see a patch, but presumably that will change soon, although Apple has been oddly slow to respond to issues like this in the past.

Most average users don’t need to worry about this bug, but if you run a web server, or any server that’s accessible from the Internet, you should make sure your version of BASH is updated.

As new information emerges, I’ll post updates here.

References:

Update 2014Sep27: The first patch for BASH didn’t fix the problem completely, but another patch that does is now available for *nix systems. Still nothing from Apple for OS X. Scans show that there are thousands of vulnerable web servers on the Internet. Existing malware is being modified to take advantage of this new vulnerability. Attacks using the BASH vulnerability are already being observed. Posts from Ars Technica, Krebs on Security and SANS have additional details.

Update #2: It looks like there are more holes to be patched in BASH.

Update 2014Oct01: Apple releases a bash fix for OS X, more vulnerabilities are discovered, and either attacks based on bash vulnerabilities are increasing or attacks are subsiding, depending on who you ask.

Update 2014Oct08: Windows isn’t affected, unless you’re using Cygwin with bash. Oddly, Apple’s OS X bash patch is not available via the App Store; you have to obtain it from the main Apple downloads site. A security researcher claims to have found evidence of a new botnet that uses the Shellshock exploit.

Update 2014Oct23: Ars Technica: Fallout of Shellshock far from over

Java 8 Update 20 released

Java 8 is not yet available from the main Java site (java.com), because it’s officially still in the developer testing/acceptance phase. The current end-user version of Java is Version 7 Update 67.

However, you can download Java 8 from the Oracle web site.

The latest version of Java 8 is Version 8 Update 20. It was made available on the Oracle site on September 18. Java 8u20 contains some new features, and fixes numerous bugs, including several security vulnerabilities.

Of particular interest to system administrators is the new Java 8 Advanced Management Console, which includes several tools that should make it easier to monitor and understand Java client systems.

This month’s Ouch! newsletter: using the Cloud

In the wake of the recent exposure of supposedly private celebrity images comes this timely look at Cloud (web-based) storage (warning: PDF). The article covers all the basics, including what you should look for in a Cloud provider, and how to keep your Cloud-based data secure (hint: use a strong password). Recommended reading for anyone currently using or considering using the Cloud for data storage.