Kayran has detected that the Version of Apache HTTP Server being used has a ‘Crash in ErrorDocument 400 handling’ vulnerability.
CVE-2015-0253 is categorized as an ‘NULL Pointer Dereference’ vulnerability (CWE-476).
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is actually NULL.
That, will probably cause a crash or an exit.
NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions.
The read_request_line function in server/protocol.c in the version of Apache being used does not initialize the protocol structure member.
That could be abused by attackers to cause Denial of Service (DoS) by sending a request that lacks a method to an installation that enables the INCLUDES filter and has an ErrorDocument 400 directive specifying a local URI.
There’s a chance that it will cause a decrease in performance and also for interruptions in the availability of resources.
To fix CVE-2015-0253, upgrade the version of Apache HTTP Server being used to 2.4.16 or higher.