Re: ldd can execute an app unexpectedly

["Dmitry V. Levin" <ldv () altlinux org>]

On Mon, Mar 07, 2011 at 06:27:05PM -0500, Steve Grubb wrote:
[...]
>  http://reverse.lostrealm.com/protect/ldd.html
>  http://www.catonmat.net/blog/ldd-arbitrary-code-execution/
>
> Besides telling everyone don't do that. ldd could take the PoV that it should only 
> call runtime linkers in trusted directories like /sbin or /usr/sbin. Or it could 
> simply detect that another linker was requested and make you add a "--force" so that 
> you are fully aware that you just let another linker run. (The suggested patch can 
> certainly be improved. But its here just in case you want it.)

In June of 2002, I suggested to change ldd to avoid invoking programs
directly, even when it seems like that would work, and invoke the dynamic
linker as a program instead.
This change was implemented at least in Owl and ALT Linux:
http://cvsweb.openwall.com/cgi/cvsweb.cgi/~checkout~/Owl/packages/glibc/glibc-2.3.6-owl-alt-ldd.diff
http://git.altlinux.org/gears/g/glibc.git?p=glibc.git;a=commitdiff;h=788577027d2950e9508a434475e04c3af864d169


-- 
ldv

Attachment: _bin
Description: