Welcome back to this month’s Patch Tuesday. Microsoft has published its monthly updates, fixing 94 vulnerabilities, 26 of which were rated as “Critical”. Two of the vulnerabilities fixed in Remote Desktop Protocol were considered extremely dangerous as they could lead to mass exploitation. The vulnerabilities are similar in nature to BlueKeep in that they are “wormable” and can rapidly infect a network of computers.
Internet Explorer and Edge
As usual, Microsoft’s browsers received their routine fixes. Microsoft has fixed several “Critical” vulnerabilities in the Chakra scripting engine, which could have been leveraged to execute code remotely. To exploit these vulnerabilities, an attacker would have to lure a victim to either a malicious or compromised website and would have privileges equal to that of the current user.
Remote Desktop Protocol
Used by thousands of IT professionals and security researchers worldwide, the Remote Desktop Protocol (RDP) is usually considered a safe and trustworthy application to connect to remote computers. However, multiple critical vulnerabilities were fixed this month in RDP. Attackers exploiting these vulnerabilities would be able to execute code remotely and spread their malicious code to any machine that connected to the infected host. These vulnerabilities are considered likely for exploit.
Office received a few fixes this month. Attackers would be able to obtain sensitive information, execute code remotely, spoof interfaces, and conduct cross-site-scripting attacks on Office web services. Several of these vulnerabilities are rated as “Critical” by Microsoft. To leverage these vulnerabilities, attackers would have to lure victims into opening malicious documents or be connected to the office web service.
Microsoft’s Bluetooth Driver was vulnerable to a key negotiation vulnerability that allowed attackers to negotiate the offered key length down to 1 byte of entropy, significantly weakening the cryptographic strength of the protocol and allowing for communication to be intercepted or injected. In order to fix this vulnerability, you have to apply registry settings manually as described in Microsoft’s guidance for CVE-2019-9506, as well as install the patch. This vulnerability is considered unlikely for exploitation.
The Windows NTFS file system is the most commonly used file system for system drives running Windows. An elevation of privilege vulnerability exists where reparse points are created by sandboxed processes on the NTFS drive, which allows for sandbox escape. By escaping the sandbox, a user would be able to elevate their privileges on an affected system. Microsoft considers this likely to be exploited.