oss-sec mailing list archives
Re: regarding CVE-2008-4382 & CVE-2008-4381
From: Nico Golde <oss-security+ml () ngolde de>
Date: Fri, 3 Oct 2008 22:18:48 +0200
Hi Steven, * Steven M. Christey <coley () linus mitre org> [2008-10-03 22:15]:
On Fri, 3 Oct 2008, Nico Golde wrote:looking at the PoC this would work in every browser supporting JavaScript as this is just a trivial memory consumption issue by passing a very large string too the alert function and thus eating memory, a simple while(true){} would be equally effective for eating cpu cycles which I wouldn't consider as a vulnerability either...I usually wouldn't call it a vulnerability, either. However, based on our analysis, the String.fromCharCode(550) creates a Unicode string for character 550, but the escape() for URL encoding can only cover 0 to 255, so it seemed like something else was going on here, maybe the alert function not working. I don't know how Javascript manages large strings, but it seems like somewhere around the "x4 += x4;" statement, you exceed multiple gigs. So maybe the alert function isn't even being reached...
I tested this already using a lower loop count in the for loops and got similar behaviour and saw the alert box. Cheers Nico -- Nico Golde - http://www.ngolde.de - nion () jabber ccc de - GPG: 0x73647CFF For security reasons, all text in this mail is double-rot13 encrypted.
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Current thread:
- regarding CVE-2008-4382 & CVE-2008-4381 Nico Golde (Oct 03)
- Re: regarding CVE-2008-4382 & CVE-2008-4381 Steven M. Christey (Oct 03)
- Re: regarding CVE-2008-4382 & CVE-2008-4381 Nico Golde (Oct 03)
- Re: regarding CVE-2008-4382 & CVE-2008-4381 Steven M. Christey (Oct 03)
- Re: regarding CVE-2008-4382 & CVE-2008-4381 Steven M. Christey (Oct 03)