CVE-2016-3301 : Détail

CVE-2016-3301

7.8
/
HIGH
A03-Injection
29.33%V3
Local
2016-08-09 19:00 +00:00
2018-10-12 17:57 +00:00

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Gestion des alertes

Descriptions

The Windows font library in Microsoft Windows Vista SP2; 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, and 1607; Office 2007 SP3; Office 2010 SP2; Word Viewer; Skype for Business 2016; Lync 2013 SP1; Lync 2010; Lync 2010 Attendee; and Live Meeting 2007 Console allows remote attackers to execute arbitrary code via a crafted embedded font, aka "Windows Graphics Component RCE Vulnerability."

Informations

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-20 Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Metrics

Metric Score Sévérité CVSS Vecteur Source
V3.0 7.8 HIGH CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.

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.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

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

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

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 9.3 AV:N/AC:M/Au:N/C:C/I:C/A:C [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 : 40255

Date de publication : 2016-08-16 22:00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=824 The GDI+ library can handle bitmaps originating from untrusted sources through a variety of attack vectors, like EMF files, which may embed bitmaps in records such as EMR_PLGBLT, EMR_BITBLT, EMR_STRETCHBLT, EMR_STRETCHDIBITS etc. The GDI+ implementation supports bitmaps compressed with the BI_RLE8 (8-bit Run-Length Encoding) compression algorithm, and performs the actual decompression in the gdiplus!DecodeCompressedRLEBitmap function. In a simplified scheme of things, let's introduce the following symbols, as they are calculated by GDI+ (all arithmetic is performed on signed 32-bit types): columns = abs(biHeight) bytes_per_row = abs(biWidth * (((biPlanes * biBitCount + 31) & 0xFFFFFFE0) / 8)) The output buffer used to store the decompressed bitmap is allocated from the heap and has a size of columns * bytes_per_row, which means the bitmap has a high degree of control over the buffer's length. One of the supported RLE escape codes is "End of Line", implemented as follows: --- cut --- out_ptr += bytes_per_row; if (out_ptr > output_buffer_end) { // Bail out. } --- cut --- The above construct seems correct at a first glance, and indeed works fine on 64-bit platforms. However, in 32-bit Large Address Aware programs which can utilize the full 32-bit address space, the "out_ptr += bytes_per_row" expression may overflow the upper address space bound (0xFFFFFFFF), which will subsequently make the "out_ptr" pointer contain a completely invalid address, while still passing the "out_ptr > output_buffer_end" sanity check. Here's an example: biWidth = 0x05900000 biHeight = 0x00000017 biPlanes = 0x0001 biBitCount = 0x0008 As a result, columns = 0x17, bytes_per_row = 0x590000 and the output buffer size is 0x7ff00000. In my test application, the buffer is allocated at address 0x7fff0020, and it ends at 0xffef0020. If we then encode the bitmap as: End of Line \ End of Line | End of Line | 24 times ... | End of Line / Repeat the 0xcc bytes 255 times. Or in binary: 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000FFCC Then the out_ptr pointer will change as follows: 7fff0020 858f0020 8b1f0020 ... ffef0020 057f0020 As you can see, the address has passed the sanity checks at all stages, and now that it is out of the allocation's bounds, an attempt to write any data will result in a crash: --- cut --- (3434.194): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. eax=0011015e ebx=ffef0020 ecx=000000fe edx=057f01cc esi=057f0020 edi=0011a6f0 eip=6b090e5a esp=0037f290 ebp=0037f2ac iopl=0 nv up ei pl nz na pe cy cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010207 gdiplus!DecodeCompressedRLEBitmap+0x195: 6b090e5a 8816 mov byte ptr [esi],dl ds:002b:057f0020=?? 0:000> ? dl Evaluate expression: 204 = 000000cc 0:000> kb ChildEBP RetAddr Args to Child 0037f2ac 6b091124 057f0020 cc11012c 0037f2cc gdiplus!DecodeCompressedRLEBitmap+0x195 0037f6f4 6b092c7a 001100f8 0011012c 00000000 gdiplus!CopyOnWriteBitmap::CopyOnWriteBitmap+0x96 0037f708 6b0932cc 001100f8 0011012c 00000000 gdiplus!CopyOnWriteBitmap::Create+0x23 0037f720 6b0c1e8b 001100f8 0011012c 00000000 gdiplus!GpBitmap::GpBitmap+0x32 0037f804 6b0c7ed1 0000004f 00143a30 0000a67c gdiplus!CEmfPlusEnumState::PlgBlt+0x92 0037f818 6b0986ca 0000004f 0000a67c 00110074 gdiplus!CEmfPlusEnumState::ProcessRecord+0xe7 0037f834 6b098862 0000004f 00000000 0000a67c gdiplus!GdipPlayMetafileRecordCallback+0x6c 0037f85c 773955ec 472127aa 0047d798 00110074 gdiplus!EnumEmfDownLevel+0x6e 0037f8e8 6b09aa36 472127aa 403581b3 6b0987f4 GDI32!bInternalPlayEMF+0x6a3 0037f920 6b09d199 472127aa 54461fd1 0137f98c gdiplus!MetafilePlayer::EnumerateEmfRecords+0x104 0037f9c8 6b09f455 00000000 54461fd1 0037faf0 gdiplus!GpGraphics::EnumEmf+0x391 0037fb28 6b0a4742 00000000 42901225 42901d0b gdiplus!GpMetafile::EnumerateForPlayback+0x7b9 0037fc24 6b0a47c6 00143228 00000000 00000000 gdiplus!GpGraphics::DrawImage+0x3f5 0037fc88 6b09c792 00143228 0037fcfc 0037fcfc gdiplus!GpGraphics::DrawImage+0x51 0037fcc0 6b09ea7a 00143228 0037fcfc 00000005 gdiplus!GpGraphics::DrawMetafileSplit+0x1f 0037fd14 6b09f4d5 00142f10 0037fda0 00000000 gdiplus!GpMetafile::ConvertToEmfPlus+0x1c1 0037fd38 6b074f71 00142f10 0037fda0 00000005 gdiplus!GpMetafile::ConvertToEmfPlus+0x1d 0037fd74 0118117e 00142f10 00143228 0037fda0 gdiplus!GdipConvertToEmfPlus+0xbf ... --- cut --- The issue has been reproduced with a C++ program built with Microsoft Visual Studio 2013 for the x86 platform and with the /LARGEADDRESSAWARE flag set, which boils down to the following code: --- cut --- Graphics graphics(hdc); Metafile *mf = new Metafile(L"C:\\path\\to\\poc.emf"); INT conversionSuccess; mf->ConvertToEmfPlus(&graphics, &conversionSuccess, Gdiplus::EmfTypeEmfPlusDual, NULL); --- cut --- The poc.emf file is attached. The reproducibility of the crash using the specific testcase is obviously highly dependent on the state of the process address space while loading the image, so poc.emf might not necessarily lead to a crash of a GDI+ client other than the test program (such as Microsoft Office). The above analysis was performed using the gdiplus.dll file found in C:\Windows\winsxs\x86_microsoft.windows.gdiplus_6595b64144ccf1df_1.1.7601.23407_none_5c02a2f5a011f9be\GdiPlus.dll on a fully patched Windows 7 64-bit operating system (md5sum c861ee277cd4e2d914740000161956ef). Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40255.zip

Products Mentioned

Configuraton 0

Microsoft>>Live_meeting >> Version 2007

Microsoft>>Lync >> Version 2010

Microsoft>>Lync >> Version 2010

Microsoft>>Lync >> Version 2013

Microsoft>>Office >> Version 2007

Microsoft>>Office >> Version 2010

Microsoft>>Skype_for_business >> Version 2016

Microsoft>>Word_viewer >> Version *

Microsoft>>Windows_10 >> Version -

Microsoft>>Windows_10 >> Version 1511

Microsoft>>Windows_10 >> Version 1607

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_vista >> Version *

References

http://www.securityfocus.com/bid/92288
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/40255/
Tags : exploit, x_refsource_EXPLOIT-DB
http://www.securitytracker.com/id/1036564
Tags : vdb-entry, x_refsource_SECTRACK
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