Steps to reproduce the issue

we have successfully saved the articles on the DR SITE server till now, logging in from a remote node
for which port opening done on DR SITE SERVER ...using jooomla 2.5.3 php version 5.3.3. After upgradation of IPS software on DR SITE, we are unable to save the artciles on the server.
Our network group has provided the description of the error as under:

The filter detects and attempts to exploit a denial-of-service vulnerability in the implementation of the hashing algorithm by multiple vendors. A denial-of-service vulnerability exists in the way of multiple vendors handle specially crafted http requests that will lead to hash collision. the below CVEs of Apache and PHP can be referred for immediate reference: CVE-2011-5034, CVE-2011-4885, CVE-2011-4858

Ater going through the error, we have upgraded the PHP from 5.3.3 to 5.6.18...a fix version available for the
above problem., Even then, there is no change in the status., we are uable to save the articles.

Expected result

when we click save and close., system should save the article on the DR SITE server and should show in the
pick list of the articles.

Actual result

the connection has timed out

System information (as much as possible)

RED HAT ENTERPIRSE LINUX 6
APACHE SERVER 2.2.15
PHP 5.6.18

Additional comments