ZDI-09-057: Microsoft Remote Desktop Client Arbitrary Code Execution Vulnerability http://www.zerodayinitiative.com/advisories/ZDI-09-057 August 11, 2009 -- CVE ID: CVE-2009-1133 -- Affected Vendors: Microsoft -- Affected Products: Microsoft Remote Desktop -- TippingPoint(TM) IPS Customer Protection: TippingPoint IPS customers have been protected against this vulnerability by Digital Vaccine protection filter ID 8379. For further product information on the TippingPoint IPS, visit: http://www.tippingpoint.com -- Vulnerability Details: This vulnerability allows attackers to execute arbitrary code on vulnerable installations of Microsoft's Remote Desktop Client. Authentication is not required to exploit this vulnerability. The specific flaw exists within mstscax.dll when parsing packets from an RDP server. A design flaw in the client allows a malicious RDP server to write to arbitrary memory inside the connecting processes memory space. By hosting a malicious RDP server, an attacker can execute arbitrary code on any client that attempts to connect to it. Privileges gained depend on which user is running the client. -- Vendor Response: Microsoft has issued an update to correct this vulnerability. More details can be found at: http://www.microsoft.com/technet/security/bulletin/MS09-044.mspx -- Disclosure Timeline: 2008-04-07 - Vulnerability reported to vendor 2009-08-11 - Coordinated public release of advisory -- Credit: This vulnerability was discovered by: * wushi of team509 and the SureRun Security Team -- 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/