Follow up: How to write a Linux virus [LWN.net]

Follow up: How to write a Linux virus

Posted Feb 13, 2009 22:28 UTC (Fri) by gat3way (guest, #47864)
In reply to: Follow up: How to write a Linux virus by alecs1
Parent article: Follow up: How to write a Linux virus

Funny enough, it depends on how the file was crafted. For example, konqueror will not see anything if you set a custom icon. And even if you don't you can always add a bunch of CRLF's to delude it.

I find another aspect of that article disturbing - the use of gksu to gain root. I never used it (being a KDE user), but now I made a quick look at it - IT IS ****** DISASTROUS!!!

You have the possibility to *remember* the root password. That's great - once you've entered it, anyone that got your rights can execute a binary as root. That's not all - this thingie is written plain wrong. It has for example format string vulnerability as shown here:

http://img99.imageshack.us/img99/8199/gksubz7.png

At least it is not a SUID binary, otherwise the consequences would be very bad...

I never knew that those KDE/Gnome devs could be such ignorant and irresponsible guys, even though I am a heavy KDE user myself. Quite embarassing...

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Follow up: How to write a Linux virus

Posted Feb 14, 2009 0:22 UTC (Sat) by alecs1 (guest, #46699) [Link]

I don't know yet how PolicyKit works, but this whole password dialog functionality seems wrong. The way I see it for desktop use, what you need is absolute control of the xserver over the local input.

This would solve for example the convenience securely enough when only one user has local access to the computer:
If you are in the high privilege group and want to execute some root command then press ctr+alt+del (invent a combination that only the kernel and xorg can read) and take absolute control on the cursor. Nothing but a local mouse can move the cursor. Show a dialog that says: "you are going to execute command_name. Click OK if you want to go on".
If an application wants to run as root, again, dialog "Please press ctrl+alt+del" to grab focus of click cancel, bla bla", then show the previous dialog where you click OK.

Reading the article on Wikipedia, Windows Vista got this right, and the few minutes I used my Vista I liked it very much: http://en.wikipedia.org/wiki/Comparison_of_privilege_auth...