Microsoft has released a security advisory indicating that it is aware of a remote attack vector for a class of vulnerabilities related to how applications load external dynamic link libraries (DLLs). If an application does not securely load DLL files, an attacker may be able to cause the application to load an arbitrary library. By convincing a user to open a file from a location that is under an attacker's control, such as a USB drive or network share, a remote attacker may be able exploit this vulnerability. Exploitation of this vulnerability may result in the execution of arbitrary code or elevation of privileges.
At this time, US-CERT is aware of reports of publicly available exploit code for this vulnerability.
US-CERT encourages users and administrators to review Microsoft security advisory 2269637 and consider implementing the workarounds listed in the document. Please note that these workarounds may reduce the functionality of the affected systems. Workarounds include
- disabling the loading of libraries from WebDAV and remote network shares
- disabling the WebClient service
- blocking TCP ports 139 and 445 at the firewall