Tools/ways for crashing a java application

Question

I have been assigned a task to crash java application running on known computer in a network (I am on same network). The java application runs on a specific IP address and port number. IP address and port number is known to me.

So far I have tried flooding (sending packets) on the specified IP/port, but no luck in crashing the app.

Can anyone suggest more tools/ways to crash the app ?

By Crash I mean -- shut the java app (kill java process).

Thanks in advance

ah... what kind of assignment is this? Is it for school? What's the application? — bchurchill, Oct 09 '14 at 23:11
@bchurchill Its a email server written in java. yea uni assigment — Script_Junkie, Oct 09 '14 at 23:13
Try jmeter (http://jmeter.apache.org/) - you can create multiple threads to try to do it. — tjg184, Oct 09 '14 at 23:32

score 0 · Answer 1 · edited Oct 07 '21 at 13:35

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Define "crashing".

If it is to test how the mail server reacts to unusual situations, see RFC 5322 for the specs and send messages that disregard them. 2.1.1. Line Length Limits as one at the beginning, for instance. Or SMTP's 4.5.3.1.8. Recipients Buffer.

edited Oct 07 '21 at 13:35

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answered Oct 09 '14 at 23:32

Gerold Broser

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by crashing i mean killing java process (which is email server). – Script_Junkie Oct 09 '14 at 23:58

score 0 · Answer 2 · answered Oct 13 '14 at 18:45

Java is notorious for leaking memory due to its garbage collection. See if you can spot a place in the mail server's code where its allocating memory that will always be reachable. That memory will never get freed. If you force this memory to be allocated over and over, preferably in a tight loop, you can probably exhaust the machine's resources.

Another thing to look for are loops or recursive calls, where you can manipulate how many times it executes. For example, if you can make a loop execute 2^31 times on demand, it's very possible the server won't be able to do anything else.

The key for an assignment like this is that you want to target the application, rather than the platform. So, it doesn't surprise me that a TCP SYN flood didn't work, especially because of the syncookies defense which is often enabled on linux.

Tools/ways for crashing a java application

2 Answers2