On Sun, 2010-06-06 at 14:08 -0400, tedd wrote: > At 1:02 AM +0100 6/6/10, Ashley Sheridan wrote: > >>On Sat, 2010-06-05 at 18:55 -0400, tedd wrote: > >> > >>Hi gang: > >> > >>Never-mind. > >> > >>I didn't change the parent directory permissions to unlink the file -- duh! > >> > >>tedd > > > >I was just about to mention this! It's one of the bizarre security > >loopholes in Linux. If you have write permissions to a directory but > >not a file within it, you can still delete the file. I believe you > >can change this behaviour with filesystem security mods, but I've > >not tried that. > > > >Ash > > Yes, I've seen where you can delete files within a directory by > changing the directory permissions. > > It's not often that my scripts create/delete files on the server -- > so I'm not up on it as much as I probably should be. > > However to me, it seems overly cautious to require scripts -- that > are already running on the server -- to have the authority (ftp id > and password) to create/delete files. After all, the scripts would > not be there if the person who placed them there didn't have > authority to create and delete files. So, I have to wonder under what > scenario would evil scripts be found/run on the server? > > For example, if anyone was going to create an evil script and place > it on the server, they must have the authority to do that. And if > they had that authority, then they could just as easily add that to > their script and side-step this requirement, right? So, what's the > purpose? > > Cheers, > > tedd > > -- > ------- > http://sperling.com http://ancientstones.com http://earthstones.com > I think it's more likely that a security flaw might be found which allows code other than yours to run. Buffer overflows were notorious for this, as they had the side-effect of running whatever ran outside of their buffer range, so you could in effect get a system with an overflow hole to run whatever code you wanted. Usually a problem like this would be limited to a specific function, but if someone was able to guess correctly that you were using this function then they could potentially form code that exploited it. I'm not an expert on this sort of thing, so what I've just said is how I roughly understand one aspect of the problem. Thanks, Ash http://www.ashleysheridan.co.uk
