Vulnerability in Microsoft CTF Protocol Goes Back To Windows XP

Posted on Tuesday August 13, 2019

CTF, a little-known Microsoft protocol used by all Windows operating system versions since Windows XP, is insecure and can be exploited with ease. From a report: According to Tavis Ormandy, a security researcher with Google's Project Zero elite security team and the one who discovered the buggy protocol, hackers or malware that already have a foothold on a user's computer can use the protocol to take over any app, high-privileged applications, or the entire OS, as a whole. Currently, there are no patches for these bugs, and a quick fix isn't expected, as the vulnerabilities are deeply ingrained in the protocol and its design. What CTF stands is currently unknown. Even Ormandy, a well-known security researcher, wasn't able to find what it means in all of Microsoft documentation. What Ormandy found out was that CTF is part of of the Windows Text Services Framework (TSF), the system that manages the text shown inside Windows and Windows applications. When users start an app, Windows also starts a CTF client for that app. The CTF client receives instructions from a CTF server about the OS system language and the keyboard input methods. It is unclear how Microsoft will patch the CTF problem.