ZDI-09-048: Microsoft Internet Explorer CSS Behavior Memory Corruption Vulnerability http://www.zerodayinitiative.com/advisories/ZDI-09-048 August 5, 2009 -- CVE ID: CVE-2009-1919 -- Affected Vendors: Microsoft -- Affected Products: Microsoft Internet Explorer -- TippingPoint(TM) IPS Customer Protection: TippingPoint IPS customers have been protected against this vulnerability by Digital Vaccine protection filter ID 8359, 8361. For further product information on the TippingPoint IPS, visit: http://www.tippingpoint.com -- Vulnerability Details: This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Internet Explorer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page. The specific flaw exists when accessing embedded style sheets within an HTML file. When modifying the properties of rules defined in the style the behavior element is improperly processed resulting in a memory corruption which can be further leveraged to execute arbitrary code under the context of the current user. -- Vendor Response: Microsoft has issued an update to correct this vulnerability. More details can be found at: http://www.microsoft.com/technet/security/Bulletin/MS09-034.mspx -- Disclosure Timeline: 2009-04-28 - Vulnerability reported to vendor 2009-08-05 - Coordinated public release of advisory -- Credit: This vulnerability was discovered by: * Peter Vreugdenhil -- About the Zero Day Initiative (ZDI): Established by TippingPoint, The Zero Day Initiative (ZDI) represents a best-of-breed model for rewarding security researchers for responsibly disclosing discovered vulnerabilities. Researchers interested in getting paid for their security research through the ZDI can find more information and sign-up at: http://www.zerodayinitiative.com The ZDI is unique in how the acquired vulnerability information is used. TippingPoint does not re-sell the vulnerability details or any exploit code. Instead, upon notifying the affected product vendor, TippingPoint provides its customers with zero day protection through its intrusion prevention technology. Explicit details regarding the specifics of the vulnerability are not exposed to any parties until an official vendor patch is publicly available. Furthermore, with the altruistic aim of helping to secure a broader user base, TippingPoint provides this vulnerability information confidentially to security vendors (including competitors) who have a vulnerability protection or mitigation product. Our vulnerability disclosure policy is available online at: http://www.zerodayinitiative.com/advisories/disclosure_policy/