=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= SilentHack.co.uk Vulnerability Research =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Background: Kmail is a HTML compatible email client that comes installed by default with the KDE desktop. This DOS requires HTML parsing to be enabled. This can be done in Kmail by going to Settings -> Configure Kmail ->Security -> and tick Prefer HTML to Plain Text. Description: Kmail can be crashed due to incorrectly parsing certain HTML elements. In this case the a combination of the and tags are incorrectly parsed leading to a segmentation fault. A sample mail can be found here http://silenthack.co.uk/nnp/exploits/kmail/tableCrash . ---- Return-Path: X-Original-To: test Delivered-To: test@torvalds Received: by torvalds (Postfix, from userid 1000) id D854F83BF5; Tue, 26 Sep 2006 16:06:36 +0100 (IST) To: test@torvalds Content-Type: text/html Subject: testing Message-Id: <20060926150636.D854F83BF5@torvalds> Date: Tue, 26 Sep 2006 16:06:36 +0100 (IST) From: nnp@torvalds (nnp) Status: R X-Status: NC X-KMail-EncryptionState: X-KMail-SignatureState: X-KMail-MDN-Sent:

---- To reproduce the crash, copy the above mail into your local mail spool file (e.g /var/mail/`whoami`) or send it to yourself (without the email headers obviously). Double click the new mail and when it opens close it again. On closing it the program should crash and give the following stack trace: [KCrash handler] #6 0xb790a334 in free () from /lib/tls/i686/cmov/libc.so.6 #7 0xb7aab8b1 in operator delete () from /usr/lib/libstdc++.so.6 #8 0xb7aab8fd in operator delete[] () from /usr/lib/libstdc++.so.6 #9 0xb6cd05d8 in non-virtual thunk to DOM::HTMLObjectBaseElementImpl::~HTMLObjectBaseElementImpl() () from /usr/lib/libkhtml.so.4 #10 0x084de030 in ?? () #11 0x084d03e8 in ?? () #12 0x00000001 in ?? () #13 0xb6e43aec in ?? () from /usr/lib/libkhtml.so.4 #14 0x084d03e8 in ?? () #15 0x00000000 in ?? () Version information: Tested on KDE 3.5.2 and kmail 1.9.1. Credits: nnp -- http://silenthack.co.uk