#Xinput test vulnerability full
#Xinput test vulnerability password

The idea that you can protect your regular user and use sudo or su safely is a very dangerous idea. Setting it to 1 forever can be a bad idea (you don't want just anyone to be able to alt+ sysrq+ e to kill xscreensaver, do you?). The value of /proc/sys/kernel/sysrq is a bitmask, so look into what it currently is and calculate what you need to convert it into to add SAK support before making it permanent in /etc/nf. You can temporarily enable them all by writing the integer 1 to /proc/sys/kernel/sysrq. On some systems, many SysRq features are disabled, including SAK.

#Xinput test vulnerability password

If there are no fake login screens trying to steal your root password (which is hopefully the case), then it simply causes agetty to restart, which should appear as nothing more than the login prompt blinking. This kills any fake login screen and brings you to the real one only. However, you must be aware that malware can hijack ctrl+ alt+ f1 and present you with a fake screen, so you must use the Secure Attention Key combination (SAK, which is alt+ sysrq+ k on Linux systems), which kills all processes in that tty. On most distros however, tty1 is a spare tty and Xorg runs on tty7). You must only use option 1, aka logging in with agetty or logind on a different tty (note that on some distros, tty1 is where Xorg is running, such as Fedora. A bash function can even hijack names that contain a / at the beginning (example based on this article): $ type /usr/bin/sudo

#Xinput test vulnerability full

Long answer: It is not true that using the full path for sudo will protect you from a malicious environment.

The same applies to su and all other programs that may be used to elevate your regular user to a more privileged one.

Use it only for convenience, not for security. Short answer: There is no way to securely use sudo if your regular user may be compromised. I will be explaining when and why you should not use sudo to elevate from your normal user to root for purely security reasons, convenience aside. It shows some of the extensive configuration possible with sudo. I will however point you to sudoers(5), which is the sudo configuration file. There are valid convenience uses for sudo, but because they are already adequately explained in other posts, I won't elaborate on them much here.