Re: chmod 111

From: Phillip Susi
Date: Fri Mar 17 2006 - 14:37:32 EST


Linus Torvalds wrote:
In particular, it's fairly easy to create a shared library that replaces a system library (LD_LIBRARY_PATH) and then just dumps out the binary image.


What prevents you from injecting a shared library and manipulating a suid executable? Does the environment get cleared when you exec a suid program? Or does the dynamic linker just notice euid != uid and ignore the LD environment variables? If so then would adding the sgid bit and making the binary owned by a powerless group effectively prevent this attack vector to read it?


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/