On Wed, Apr 18, 2012 at 07:04, Kurt Seifried <kseifr...@redhat.com> wrote: >> In addition munin parses parts of the query string. You are allowed >> to modify the size of the image. By choosing a path >> "....png?size_x=20000&size_y=20000&uniquestuff" you can do the >> same attack while simultaneously using a large image size. The raw >> image would be 381M (assuming 8bits/pixel) in this case. A png >> version will likely be smaller, say 4M? So now you have an >> amplification of 4M/request. Note that this query can get a node >> into swapping, because rrdtool needs to create the whole image in >> main memory.
> Ouch. I believe I fixed the bug in r4825, since : - url with query string aren't stored permanently anymore. - /tmp isn't used anymore per default (to fix #668536) Could you confirm that ? OTOH, the issue about very big imgs that gets the cgi into swapping isn't the same bug to be. As Helmut noticed, there is already a size cap in rrd, so do I still need implement one in munin ? If yes, would you mind to file another bugreport (for RAM exhaustion) ? Thx ! r4825: http://munin-monitoring.org/changeset/4825 -- Steve Schnepp http://blog.pwkf.org/ -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
