> Without read permissions you cannot execute the binary
This is not correct, as when the binary is setuid-someone-else, you are not the one executing it; they are.
$ cat hello.c
#include <stdio.h>
int main(void)
{
(void) puts("Hello, world!");
return 0;
}
$ clang-21 -Weverything hello.c -o hello
$ sudo chown root:root hello
$ sudo chmod 4711 hello
$ ls -l hello
-rws--x--x 1 root root 16056 Apr 30 22:22 hello
$ ./hello
Hello, world!
$ id
uid=1000(aaron) gid=1000(aaron) groups=1000(aaron),27(sudo),46(plugdev),100(users)
Removing world-readability from all setuid-root binaries on the system would be sufficient to kill the PoC script provided for this vulnerability. It would not be sufficient to prevent exploitation though; there are many ways to abuse the ability to write to files you have read access to in order to gain root, for example by using the vulnerability to alter the cached copy of a file in /etc/sudoers.d/, or overwrite /etc/passwd, or /etc/crontab, ... the list goes on.
interesting but in that case no point in keeping the x bit either and suid binaries should just be 4700 ?