> This "garbage" is exactly what you allowed to add via crafted request > (curl -H ... etc). Why you want to allow so?
I don't want to. It was "allowed" until now, as X-Forwarded-For headers were not deleted by the reverse proxy. I still think that many people are using Debian and mod_rpaf, and are not deleting these headers. Won't you do anything for them ? > > (so the request has two X-Forwarded-For headers when it arrives > > on the web front end, one is malicious, one is correct from a trusted > > source). > > > > A workaround could be stripping the previous X-Forwarded-For headers on the > > reverse proxy, but it shouldn't be necessary. > > Usually, you can just ignore X-Forwarded-For, provided by client. This > case covers typical simple frontend+backend setup. > > Of course, this shouldn't be necessary - but it's a good idea to expose > less headers for modification to client, right? Agreed. Still, there's a bug, and this "solution" is - a "best practice" but - only a workaround to this bug. My point is: allright, we should all harden our setups, but: * many people don't and it shouldn't be necessary for Apache2 to keep running * there are no words about it in the docs provided by Debian : /usr/share/doc/libapache2-mod-rpaf/README.Debian Module configuration is pretty simple, there are only two directives to set; RPAFenable and RPAFproxy_ips. With the later you can define which IP's are your frontend proxies that sends the correct X-Forwarded-For headers. If you do not use the RPAFproxy_ips directive then the module will not change the remote address of the incoming connection at any time. * The bug is exposed by the ipv6 patch which has been applied by Debian. I cannot reproduce the segfaults with upstream sources. There is likely to be an issue with upstream code, but the NULL pointer dereference has been introduced by Debian. Cheers -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org