ZDI-11-091: (0day) Cisco Secure Desktop CSDWebInstaller Remote Code Execution Vulnerability http://www.zerodayinitiative.com/advisories/ZDI-11-091 February 23, 2011 -- CVE ID: CVE-2011-0926 -- CVSS: 9, (AV:N/AC:L/Au:N/C:P/I:P/A:C) -- Affected Vendors: Cisco -- Affected Products: Cisco Secure Desktop -- TippingPoint(TM) IPS Customer Protection: TippingPoint IPS customers have been protected against this vulnerability by Digital Vaccine protection filter ID 8247. 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 Cisco Secure Desktop. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within CSDWebInstaller.ocx ActiveX control. The vulnerable Cisco-signed ActiveX control verifies the signing authority names in the certificate chain but fails to properly verify the digital signature of an executable file that is downloaded and executed by the Cisco Secure Desktop installation process. A remote attacker can exploit this vulnerability to execute arbitrary code under the context of the browser. -- Vendor Response: February 23, 2011 - This vulnerability is being disclosed publicly without a patch in accordance with the ZDI 180 day deadline. -- Mitigations: Cisco states that they will have a patch for this issue on March 31st, 2011. In the meantime, we suggest users implement the mitigations below. The killbit can be set on this control to disable scripting within Internet Explorer by modifying the data value of the Compatibilty Flags DWORD within the following location in the registry: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\705EC6D4-B138-4079-A307-EF13E4889A82 If the Compatibility Flags value is set to 0x00000400 the control can no longer be instantiated inside the browser. For more information, please see: http://support.microsoft.com/kb/240797 -- Disclosure Timeline: 2010-09-14 - Vulnerability reported to vendor 2011-02-23 - Coordinated public release of advisory -- Credit: This vulnerability was discovered by:full * Anonymous -- 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/ Follow the ZDI on Twitter: http://twitter.com/thezdi