Emirates Mac

Apple, Mac, and iPod in the United Arab Emirates UAE

‘Severe security hole in Apple Safari Browser’

Posted by emiratesmac on 21 February, 2006

There seems to be another vulnerability in Safari:

As the German IT portal heise online [in German] conveys, a new security hole in the Safari webbrowser for Apple’s Mac OS X has been discovered. This security hole is rather severe, as it invokes the execution of shell scripts under certain circumstances.

Once again the Safari option “open ’safe’ files automatically after downloadâ€? bears the blame. If this facility runs across a shell script that is missing the so-called Shebang-row, the system won’t ask the user whether to execute the file automatically anymore – it’ll just execute it anyways. Unfortunately you can simply rename a shellscript without a Shebang-row to known-good filetype extensions like JPG or PNG and put that renamed script into a ZIP file – zipping as well an administrative file that’ll connect that file with the shell. A target Mac then “knowsâ€? automatically how to open that file if it receives that ZIP – it’ll take it as totally normal to execute the “jpg fileâ€? with the shell.

To circumvent this issue immediately, you can exercise two countermeasures – the first one is to disable that unsafe option in Safari, the second one is to move the terminal to another place, as the connection between shellscript and terminal has a hardcoded file path to the terminal. Additionally, you should never ever work with administrator privileges – as one should be used to with windoze, this rule of thumb has the same virtues on a Mac as well.

[posted with ecto]

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