I've recently installed the serendipity software (version 1.6.2). After installation everything seemed to work fine. When I tried to change some settings in the admin, in particular administration -> Configuration I was getting a 403 error every time I tried to submit this form.
As everything else on the site was working fine, I contacted my host. It turned out there was a mod_security setting that was blocking that page.
Below is the rule that is causing the 403:
Message: Access denied with code 403 (phase 2). Pattern match "(?:/(?:etc|proc|var/tmp|usr|opt|s?bin|dev|tmp|kern|[br]oot|sys|windows|winnt)/|(?:\\/|\\\\)+inetpub|localstart\\.asp|boot\\.ini)" at ARGS:convert. [file "/usr/local/apache/conf/modsec/10_asl_rules.conf"] [line "216"] [id "340009"] [rev "27"] [msg "Atomicorp.com - FREE UNSUPPORTED DELAYED FEED - WAF Rules: Protected Path Access denied in URI/ARGS"] [data ""] [severity "CRITICAL"]
Referer: http://xxxxxxxxxx.co.uk/blog/serendipit ... erendipity[adminModule]=configuration
It looks like it doesn't like the path to the convert binary in the 'Image Conversion Settings'.
Just hope that this might help other people who have similar 'unexplained' 403 errors.
Keep up the good work, this is by far the best blog software I've come across