CVE-2017-8483 : Détail

CVE-2017-8483

5
/
Moyen
A01-Broken Access Control
5.21%V4
Local
2017-06-14
23h00 +00:00
2017-08-11
13h57 +00:00
CVE.org
NVD
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Descriptions du CVE

The kernel in 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, 1703, and Windows Server 2016 allows an authenticated attacker to obtain information via a specially crafted application. aka "Windows Kernel Information Disclosure Vulnerability," a different vulnerability than CVE-2017-8492, CVE-2017-8491, CVE-2017-8490, CVE-2017-8489, CVE-2017-8488, CVE-2017-8485, CVE-2017-8482, CVE-2017-8480, CVE-2017-8479, CVE-2017-8478, CVE-2017-8476, CVE-2017-8474, CVE-2017-8469, CVE-2017-8462, CVE-2017-0300, CVE-2017-0299, and CVE-2017-0297.

Informations du CVE

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.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.0 5 MEDIUM CVSS:3.0/AV:L/AC:L/PR:L/UI:R/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.

Required

Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited. For example, a successful exploit may only be possible during the installation of an application by a system administrator.

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

 nvd@nist.gov
V2 1.9 AV:L/AC:M/Au:N/C:P/I:N/A:N nvd@nist.gov

EPSS

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

Score EPSS

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.

Percentile EPSS

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.
EPSS First.org

Informations sur l'Exploit

Exploit Database EDB-ID : 42243

Date de publication : 2017-06-22 22h00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1213 We have encountered a Windows kernel crash in the ATMFD.DLL OpenType driver while processing a corrupted OTF font file, see below: --- DRIVER_PAGE_FAULT_BEYOND_END_OF_ALLOCATION (d6) N bytes of memory was allocated and more than N bytes are being referenced. This cannot be protected by try-except. When possible, the guilty driver's name (Unicode string) is printed on the bugcheck screen and saved in KiBugCheckDriver. Arguments: Arg1: fb69b01e, memory referenced Arg2: 00000000, value 0 = read operation, 1 = write operation Arg3: 8f635862, if non-zero, the address which referenced memory. Arg4: 00000000, (reserved) Debugging Details: ------------------ [...] FAULTING_IP: ATMFD+35862 8f635862 803802 cmp byte ptr [eax],2 MM_INTERNAL_CODE: 0 CPU_COUNT: 4 CPU_MHZ: da3 CPU_VENDOR: GenuineIntel CPU_FAMILY: 6 CPU_MODEL: 3e CPU_STEPPING: 4 CPU_MICROCODE: 6,3e,4,0 (F,M,S,R) SIG: 19'00000000 (cache) 19'00000000 (init) DEFAULT_BUCKET_ID: WIN7_DRIVER_FAULT BUGCHECK_STR: 0xD6 PROCESS_NAME: csrss.exe CURRENT_IRQL: 2 ANALYSIS_SESSION_HOST: WIN7-32-VM ANALYSIS_SESSION_TIME: 03-21-2017 10:49:20.0375 ANALYSIS_VERSION: 10.0.10586.567 x86fre LAST_CONTROL_TRANSFER: from 8f636088 to 8f635862 STACK_TEXT: WARNING: Stack unwind information not available. Following frames may be wrong. 9625f538 8f636088 9625f790 05f70000 9625f790 ATMFD+0x35862 9625f630 8f6355b1 9625f790 05f70000 9625f64c ATMFD+0x36088 9625f734 8f635711 9625f790 05f70000 9625f868 ATMFD+0x355b1 9625f768 8f6051b0 00000000 9625f790 05f70000 ATMFD+0x35711 9625f808 8f607279 00000004 00000001 00000002 ATMFD+0x51b0 9625f888 8f603d14 00000000 00000000 94bb3200 ATMFD+0x7279 9625f96c 8f6e7b8d 00000004 fbad2fc0 fbadaff8 ATMFD+0x3d14 9625f9b4 8f6e7adf 00000001 fbad2fc0 fbadaff8 win32k!PDEVOBJ::LoadFontFile+0x3c 9625f9f4 8f6e74fc ffa6a130 0000002e fbad2fc0 win32k!vLoadFontFileView+0x291 9625fa80 8f6d6403 9625fb58 0000002e 00000001 win32k!PUBLIC_PFTOBJ::bLoadFonts+0x209 9625facc 8f6d73d8 9625fb58 0000002e 00000001 win32k!GreAddFontResourceWInternal+0xfb 9625fc14 8164ddb6 000d9b78 0000002e 00000001 win32k!NtGdiAddFontResourceW+0x142 9625fc14 77ad6c74 000d9b78 0000002e 00000001 nt!KiSystemServicePostCall --- The bugcheck is caused by an attempt to read memory from an unmapped address. The specific expression being dereferenced by ATMFD.DLL is "base address of the Name INDEX data + NAME.offset[x] - 1", however no bounds checking is performed over the value of NAME.offset[x] before using it for pointer arithmetic. To our current knowledge, this condition can only lead to an out-of-bounds read, thus limiting the impact of the bug to remote denial of service, or potentially local kernel memory disclosure. However, we have not fully confirmed that the severity of the bug is not in fact more significant due to some further ATMFD logic we are not aware of. Interestingly, the crash is almost identical to the one reported in Issue #386 (MSRC-30296) nearly two years ago, which was supposedly fixed as CVE-2015-2461 in the MS15-080 bulletin. The fact that the same bugcheck still reproduces can potentially mean that the patch was insufficient. Only a single bitflip applied to a valid font file is sufficient to create an offending testcase (excluding SFNT table checksums). In our case, the byte at offset 0x375 in the original sample must be changed from 0x01 to 0x41. This corresponds to offset 0x71 of the "CFF " table. The PoC font can be found attached to this tracker entry. The issue reproduces on Windows 7 (other platforms untested). It is easiest to reproduce with Special Pools enabled for ATMFD.DLL, leading to an immediate crash when the bug is triggered. The bugcheck occurs upon opening the font in any default utility such as the Windows Font Viewer -- no special tools are required. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/42243.zip

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_2008 >> Version r2

Microsoft>>Windows_server_2012 >> Version -

Microsoft>>Windows_server_2012 >> Version r2

Microsoft>>Windows_server_2016 >> Version -

Références

http://www.securityfocus.com/bid/98859
Tags : vdb-entry, x_refsource_BID
http://www.securitytracker.com/id/1038659
Tags : vdb-entry, x_refsource_SECTRACK
https://www.exploit-db.com/exploits/42243/
Tags : exploit, x_refsource_EXPLOIT-DB