The Snort IDS rule provided is designed to detect traffic patterns indicative of attempts to exploit CVEs related to RDP (Remote Desktop Protocol). Specifically, it looks for the presence of the string "MS_T120" in TCP traffic on port 3389, which is commonly used for RDP.
To mitigate vulnerabilities associated with RDP, including those detected by this Snort rule, one of the most effective measures is OS patching. Many CVEs affecting RDP are addressed through security updates and patches provided by operating system vendors (e.g., Microsoft for Windows systems). By ensuring that systems are regularly updated with the latest patches, organizations can mitigate the risk of exploitation via RDP vulnerabilities.