VUPEN Security Research - Microsoft Internet Explorer CSS @import Memory Corruption (Pwn2Own 2014) Website : http://www.vupen.com Twitter : http://twitter.com/vupen I. BACKGROUND --------------------- "Microsoft Internet Explorer is a web browser developed by Microsoft and included as part of the Microsoft Windows line of operating systems with more than 60% of the worldwide usage share of web browsers." (Wikipedia) II. DESCRIPTION --------------------- VUPEN Vulnerability Research Team discovered a critical vulnerability in Microsoft Internet Explorer. The vulnerability is caused by a use-after-free vulnerability when manipulating CSS @import statements through "addImport()" or "removeImport()", which could be exploited by attackers to leak arbitrary memory or execute arbitrary code via a malicious web page. III. AFFECTED PRODUCTS --------------------------- Microsoft Internet Explorer 11 Microsoft Internet Explorer 10 Microsoft Internet Explorer 9 IV. SOLUTION ---------------- Apply MS14-037 security update. V. CREDIT -------------- This vulnerability was discovered by VUPEN Security. VI. ABOUT VUPEN Security --------------------------- VUPEN is the leading provider of defensive and offensive cyber security intelligence and advanced zero-day research. All VUPEN's vulnerability intelligence results exclusively from its internal and in-house R&D efforts conducted by its team of world-class researchers. VUPEN Solutions: http://www.vupen.com/english/services/ VII. REFERENCES ---------------------- https://technet.microsoft.com/library/security/ms14-037 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-1763 VIII. DISCLOSURE TIMELINE ----------------------------- 2014-01-24 - Vulnerability Discovered by VUPEN Security 2014-03-14 - Vulnerability Reported to ZDI / Microsoft During Pwn2Own 2014 2014-07-08 - Vulnerability Fixed by Microsoft 2014-07-16 - Public disclosure