How Poor Punctuation Can Break Windows

An anonymous reader writes with a report at Ars Technica about how a small bug can lead to a security problem. In this case, the problem is that quotation marks — or the lack of them — can be significant. From the Ars article: "The scenario... requires a 'standard' user with access rights to create a directory to a fileserver and an administrator executing a vulnerable script," Frank Lycops and Raf Cox, security researchers with The Security Factory, said in an e-mail interview. "This allows the attacker to gain the privileges of the user running the script, thus becoming an administrator." While the attack falls short of the severity of the Shellshock family of Linux shell vulnerabilities, the two researchers stressed that it's a good example of how untrusted input can be used to execute commands on a system. The researchers identified at least one popular script with the vulnerability. When the script attempts to set the starting directory for system administration work, it inadvertently runs the command appended to the malicious directory's name as well. ... The solution is to use proper coding practices—in this case, the judicious use of quotation marks. Quotation marks are used in the shell environment to make sure that the data inside the quotes is not interpreted by the program as a command.

Comments

Re:Shellshock is way worse

[Toreo asesino]

This "patched within hours" is a bit of a false economy if you need to test your apps aren't going to be negatively impacted. If you don't care or just want to live the dream then yeah, otherwise the real world is a bit more complicated than that. The fact the patch needed patching in itself suggest some testing will be needed if you care about top-to-bottom stability.