Directory permissions question
in [General]
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From: Peter Lind on 19 Apr 2010 12:06 On 19 April 2010 17:18, Al <news(a)ridersite.org> wrote: > > > On 4/19/2010 11:11 AM, Adam Richardson wrote: >> >> On Mon, Apr 19, 2010 at 10:59 AM, Al<news(a)ridersite.org> Â wrote: >> >>> I'm working on a hosted website that was hacked and found something I >>> don't >>> fully understand. Thought someone here may know the answer. >>> >>> The site has 4 php malicious files in directories owned by "system" [php >>> created dirs on the site are named "nobody"] and permissions 755. >>> >>> Is there any way the files could have been written other than by ftp >>> access >>> or at the host root level? Clearly a php script couldn't. >>> >>> Thanks, Al.......... >>> >>> -- >>> PHP General Mailing List (http://www.php.net/) >>> To unsubscribe, visit: http://www.php.net/unsub.php >>> >>> >> Are there any other programming options enabled on the account (Perl, JSP, >> Ruby, etc?) Â Even if the files are PHP, any of those programming options >> can >> be configured to create the files. >> >> Additionally, a vulnerability in one of the libraries leveraged to provide >> the hosting environment could also have provided the entry (PHP makes for >> a >> capable deliverable, but it doesn't have to provide the key for a hacking >> situation.) >> >> Adam >> > > Are Perl, JSP, Ruby, etc. able to ignore the dir ownership and write > permissions on a Linux/Apache system? > I've seen an install of Trac hacked by a file-upload - it managed to write a cron job, which then wrote to other files. It's not just a question of whether your Apache server has the correct rights/permissions, it's equally a question of: is any other part of the system getting used against me. Regards Peter -- <hype> WWW: http://plphp.dk / http://plind.dk LinkedIn: http://www.linkedin.com/in/plind Flickr: http://www.flickr.com/photos/fake51 BeWelcome: Fake51 Couchsurfing: Fake51 </hype>
From: Nathan Rixham on 20 Apr 2010 13:44
Al wrote: > I'm working on a hosted website that was hacked and found something I > don't fully understand. Thought someone here may know the answer. > > The site has 4 php malicious files in directories owned by "system" [php > created dirs on the site are named "nobody"] and permissions 755. > > Is there any way the files could have been written other than by ftp > access or at the host root level? Clearly a php script couldn't. > > Thanks, Al.......... it doesn't matter what the language of the script that did this is, it's all about the permissions of the process that's running the script it's the difference between you running a script as www-data and running it via the shell as root. SUExec might be at play, some other process, some user with ssh access, some back door, consider the permissions and owner of the directory containing the files, if it's nobody then anybody could have written to it. All in, ask the ISP to check logs and history, ensure all your permissions on directories are tight, and that you don't have any scripts on there that can be abused and that they are "safe" - then you're clear :) Best, Nathan |