Re: Secure Apache Webserver
On Sun, Oct 29, 2006 at 03:20:25PM +0100, Aiko Barz wrote: Hello, I already discussed this subject on the list. There were several possible solutions for this subject and I have chosen one, I would like to present now. The problem: I have several vhosts, which are used by several people. The Apache is running with $UID 67. Users can access the system by using scponly, which is jailed into /var/www. No problem here so far. This issue was, that all scripts must be readable or even writeable for the Apache Webserver. So one hacked page could damage other vhosts by writing some PHP code to access the other vhosts within /var/www. My solution: 1. I made SuExec working within the chroot environment. (http://www.openbsdsupport.org/ApacheSuexecChroot.html) 2. I wrote a patch for suexec.c to handle *.php correctly. (http://files.haeckser.net/haeckser.net/suexec.patch) 3. I compiled PHP by my own with CGI-support and moved the binary into the chroot. 4. I removed mod_php and mod_perl and set the Apache directives User, Group, AddHandler cgi-script and Options +ExecCGI. Now, every PHP-script has the permissions 700 and gets executed with its own $UID. I feel much better now. :) I believe it is possible to set this up using FastCGI, which will actually be (reasonably?) fast too. Yes, I am a FastCGI fanboy. Joachim
Re: Secure Apache Webserver
Joachim Schipper wrote: I believe it is possible to set this up using FastCGI, which will actually be (reasonably?) fast too. Yes, I am a FastCGI fanboy. I just spent the whole day setting up FastCGi using www/mod_fastcgi and www/fcgi. I ended up with a server process, written C, that runs outside the apache chroot as a FastCGIExternalServer and Apache communicating with this through mod_fastcgi using an AF_UNIX socket. The fastcgi server connects to a PostgreSQL database to do stuff, and yes, this setup is fucking fast. And of course it does not have the security problems PHP has, the slowness of CGI nor the overhead of Zope...
Re: Secure Apache Webserver
On 2006/09/29 11:16, Toni Mueller wrote: On Thu, 28.09.2006 at 09:47:51 -0400, James Strandboge [EMAIL PROTECTED] wrote: Its extra work, but you could setup completely different chroots for each domain. This way each domain is isolated and you can tailor each one to the user's needs. with this, you quickly run into the problem of consuming too many IP numbers, or do you have good argumentation against RIPE's objections? not necessarily, you can put a reverse proxy in front.
Re: Secure Apache Webserver
On Thu, Sep 28, 2006 at 05:48:26PM +0200, Joachim Schipper wrote: On Thu, Sep 28, 2006 at 12:52:41PM +0200, Joachim Schipper wrote: On Thu, Sep 28, 2006 at 10:55:30AM +0200, Aiko Barz wrote: The issue: If my users start to install a php-Filebrowser, they are able to access the other Webdirectories and could read config.php, because they are doing it with the permissions of the webserver. Write access would be possible as well, since some parts need to have write access. suExec + PHP is not feasible for many people, due to the high webserver load incurred; suPHP may be less problematic, or not. It appears, from a quick web search, that FastCGI allows one to give each user its own PHP instance. Yes--wrap fastCGI daemons in suExec. Each fastcgi process runs with uid/gid of site owner. Use dynamic servers and make 'em die out fast. If a site is busy, servers will stay resident and site is fast. Low volume sites are slow on first hit, as new server needs to spawn. A side benefit is that you can specify a different php.ini for each vhost. Fix your umask for FTP server so other doesn't have read permissions for newly uploaded files. Turn search bit off for other users in as many directories in your vhost tree as possible. Expect to spend a couple days getting it right. ;) m
Re: Secure Apache Webserver
* Aiko Barz [EMAIL PROTECTED] [2006-09-28 10:59]: Hi *, I use OpenBSD+Apache+Chroot for my webservices. The users can access their vhosts by using scponly, which is chrooted into /var/www as well. /htdocs/www.example.net belongs to theuser:www and has the permissions rwxr-x---. The issue: If my users start to install a php-Filebrowser, they are able to access the other Webdirectories and could read config.php, because they are doing it with the permissions of the webserver. php safe mode and basedir (set per vhost of course) can help there. -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de Full-Service ISP - Secure Hosting, Mail and DNS Services Dedicated Servers, Rootservers, Application Hosting - Hamburg Amsterdam
Re: Secure Apache Webserver
On Thu, Sep 28, 2006 at 10:55:30AM +0200, Aiko Barz wrote: Hi *, I use OpenBSD+Apache+Chroot for my webservices. The users can access their vhosts by using scponly, which is chrooted into /var/www as well. /htdocs/www.example.net belongs to theuser:www and has the permissions rwxr-x---. The issue: If my users start to install a php-Filebrowser, they are able to access the other Webdirectories and could read config.php, because they are doing it with the permissions of the webserver. Write access would be possible as well, since some parts need to have write access. I started to patch suExec to make it handle *.php and to make it chroot-ready, but I wasn't successful so far. suPHP seems to have issues with 1.3.29 and ordering new IP-addressese for having multible webserver intances seems to be difficult. As Henning pointed out, PHP's open_basedir and friends can be useful, although I would caution against believing they will actually work - many problems have been discovered that would allow an attacker to bypass open_basedir and uid/gid checks. Notably, assuming one can put passwords and such in config.php is probably not a good idea (Apache allows setting php_flags for this, which can be made to be secure). It might be enough to keep people out of each others' directories, though. suExec + PHP is not feasible for many people, due to the high webserver load incurred; suPHP may be less problematic, or not. For now, I'm just running a dedicated server, so I've not yet encountered this problem personally. Joachim
Re: Secure Apache Webserver
On Thu, Sep 28, 2006 at 12:52:41PM +0200, Joachim Schipper wrote: On Thu, Sep 28, 2006 at 10:55:30AM +0200, Aiko Barz wrote: Hi *, I use OpenBSD+Apache+Chroot for my webservices. The users can access their vhosts by using scponly, which is chrooted into /var/www as well. /htdocs/www.example.net belongs to theuser:www and has the permissions rwxr-x---. The issue: If my users start to install a php-Filebrowser, they are able to access the other Webdirectories and could read config.php, because they are doing it with the permissions of the webserver. Write access would be possible as well, since some parts need to have write access. I started to patch suExec to make it handle *.php and to make it chroot-ready, but I wasn't successful so far. suPHP seems to have issues with 1.3.29 and ordering new IP-addressese for having multible webserver intances seems to be difficult. As Henning pointed out, PHP's open_basedir and friends can be useful, although I would caution against believing they will actually work - suExec + PHP is not feasible for many people, due to the high webserver load incurred; suPHP may be less problematic, or not. Replying to myself to add another thought... It appears, from a quick web search, that FastCGI allows one to give each user its own PHP instance. One final thought: it would be better to use /virtual, as the Apache docs recommend, to prevent a misconfiguration giving access to everything in /htdocs. Or, at least, create a /htdocs/index.html. Joachim
