Intermittent Http 403 Forbidden Error Calling Same Ajax Code

I use my JavaScript client (say, foo.js) to call my php Ajax code in the server (say, bar.php). This works perfectly most of the time, but once in a while I get back HTTP 403 (Forb

Solution 1:

Did some thorough research. It's... mod_security !!!

Look at http://www.opensourceforu.com/2011/08/securing-apache-part-10-mod_security/ , search for 'SecFilterScanPOST'. My 'aaa' posted variable serves as some random token, and once in a while had a value filtered by this mod_security mechanism.

This was fixed following a chat with the host support. Initially I thought I could solve it myself by editing some .htaccess file(s) appropriately, but eventually it appeared I needed their assistance.