CVE-2017-8731 : Detail

CVE-2017-8731

7.5
/
High
Overflow
66.53%V3
Network
2017-09-12
23h00 +00:00
2017-09-21
07h57 +00:00
CVE.org
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CVE Descriptions

Microsoft Edge in Microsoft Windows 10 1607 and Windows Server 2016 allows an attacker to execute arbitrary code in the context of the current user, due to the way that Microsoft Edge accesses objects in memory, aka "Microsoft Edge Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8734, CVE-2017-8751, and CVE-2017-11766.

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.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 42758

Publication date : 2017-09-18 22h00 +00:00
Author : Google Security Research
EDB Verified : Yes

Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1309 There is a security issue in Microsoft Edge related to how HTML documents are loaded. If Edge displays a HTML document from a slow HTTP server, it is possible that a part of the document is going to be rendered before the server has finished sending the document. It is also possible that some JavaScript code is going to trigger. By making DOM modifications before the document had a chance of fully loading, followed by another set of DOM modifications afer the page has been loaded, it is possible to trigger memory corruption that could possibly lead to an exploitable condition. A debug log is included below. Note that the crash RIP directly preceeds a (CFG-protected) indirect call, which demonstrates the exploitability of the issue. Since a custom HTTP server is needed to demonstrate the issue, I'm attaching all of the required code. Simply run server.py and point Edge to http://127.0.0.1:8000/ Note: this has been tested on Microsoft Edge 38.14393.1066.0 (Microsoft EdgeHTML 14.14393) Debug log: ========================================= (a68.9c0): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0x1389aa: 00007ffa`9d5f15ea 488b01 mov rax,qword ptr [rcx] ds:00000000`abcdbbbb=???????????????? 0:013> k # Child-SP RetAddr Call Site 00 000000eb`c42f8da0 00007ffa`9d8b243d edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0x1389aa 01 000000eb`c42f8dd0 00007ffa`9d8b28e2 edgehtml!Collections::SGrowingArray<TSmartPointer<Tree::ANode,CStrongReferenceTraits> >::DeleteAt+0x89 02 000000eb`c42f8e00 00007ffa`9d8b0cd7 edgehtml!Undo::UndoNodeList::RemoveNodesCompletelyContained+0x5e 03 000000eb`c42f8e30 00007ffa`9d8ad79b edgehtml!Undo::WrapUnwrapNodeUndoUnit::RemoveNodesAtOldPosition+0x33 04 000000eb`c42f8e70 00007ffa`9d5b303d edgehtml!Undo::MoveForestUndoUnit::HandleWrapUnwrap+0x6b 05 000000eb`c42f8f10 00007ffa`9d8ac629 edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0xfa3fd 06 000000eb`c42f8f60 00007ffa`9d5b3085 edgehtml!Undo::ParentUndoUnit::ApplyScriptedOperationToChildren+0xb5 07 000000eb`c42f8ff0 00007ffa`9d11035c edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0xfa445 08 000000eb`c42f9040 00007ffa`9d110125 edgehtml!Undo::UndoManager::ApplyScriptedOperationsToUserUnits+0x11c 09 000000eb`c42f9130 00007ffa`9d1d6f0d edgehtml!Undo::UndoManager::SubmitUndoUnit+0x125 0a 000000eb`c42f9170 00007ffa`9dc9c9ae edgehtml!CSelectionManager::CreateAndSubmitSelectionUndoUnit+0x141 0b 000000eb`c42f9200 00007ffa`9dc90b70 edgehtml!CRemoveFormatBaseCommand::PrivateExec+0xae 0c 000000eb`c42f92c0 00007ffa`9dc9057a edgehtml!CCommand::Exec+0xe8 0d 000000eb`c42f9350 00007ffa`9d55e481 edgehtml!CMshtmlEd::Exec+0x17a 0e 000000eb`c42f93b0 00007ffa`9d39cc34 edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0xa5841 0f 000000eb`c42f9470 00007ffa`9d21d6a1 edgehtml!CDoc::ExecHelper+0x5d18 10 000000eb`c42fb020 00007ffa`9d1dbb57 edgehtml!CDocument::Exec+0x41 11 000000eb`c42fb070 00007ffa`9d1dba25 edgehtml!CBase::execCommand+0xc7 12 000000eb`c42fb0f0 00007ffa`9d1db8ac edgehtml!CDocument::execCommand+0x105 13 000000eb`c42fb2e0 00007ffa`9d498155 edgehtml!CFastDOM::CDocument::Trampoline_execCommand+0x124 14 000000eb`c42fb3f0 00007ffa`9c930e37 edgehtml!CFastDOM::CDocument::Profiler_execCommand+0x25 15 000000eb`c42fb420 00007ffa`9c9e9073 chakra!Js::JavascriptExternalFunction::ExternalFunctionThunk+0x177 16 000000eb`c42fb500 00007ffa`9c9596cd chakra!amd64_CallFunction+0x93 17 000000eb`c42fb560 00007ffa`9c95cec7 chakra!Js::InterpreterStackFrame::OP_CallCommon<Js::OpLayoutDynamicProfile<Js::OpLayoutT_CallIWithICIndex<Js::LayoutSizePolicy<0> > > >+0x15d 18 000000eb`c42fb600 00007ffa`9c960f52 chakra!Js::InterpreterStackFrame::OP_ProfiledCallIWithICIndex<Js::OpLayoutT_CallIWithICIndex<Js::LayoutSizePolicy<0> > >+0xa7 19 000000eb`c42fb680 00007ffa`9c95f1b2 chakra!Js::InterpreterStackFrame::ProcessProfiled+0x132 1a 000000eb`c42fb710 00007ffa`9c963280 chakra!Js::InterpreterStackFrame::Process+0x142 1b 000000eb`c42fb770 00007ffa`9c9649c5 chakra!Js::InterpreterStackFrame::InterpreterHelper+0x4a0 1c 000000eb`c42fbad0 00000284`bf4b0fa2 chakra!Js::InterpreterStackFrame::InterpreterThunk+0x55 1d 000000eb`c42fbb20 00007ffa`9c9e9073 0x00000284`bf4b0fa2 1e 000000eb`c42fbb50 00007ffa`9c9580c3 chakra!amd64_CallFunction+0x93 1f 000000eb`c42fbba0 00007ffa`9c95abc0 chakra!Js::JavascriptFunction::CallFunction<1>+0x83 20 000000eb`c42fbc00 00007ffa`9c95f65d chakra!Js::InterpreterStackFrame::OP_CallI<Js::OpLayoutDynamicProfile<Js::OpLayoutT_CallI<Js::LayoutSizePolicy<0> > > >+0x110 21 000000eb`c42fbc50 00007ffa`9c95f217 chakra!Js::InterpreterStackFrame::ProcessUnprofiled+0x32d 22 000000eb`c42fbce0 00007ffa`9c963280 chakra!Js::InterpreterStackFrame::Process+0x1a7 23 000000eb`c42fbd40 00007ffa`9c9649c5 chakra!Js::InterpreterStackFrame::InterpreterHelper+0x4a0 24 000000eb`c42fc090 00000284`bf4b0faa chakra!Js::InterpreterStackFrame::InterpreterThunk+0x55 25 000000eb`c42fc0e0 00007ffa`9c9e9073 0x00000284`bf4b0faa 26 000000eb`c42fc110 00007ffa`9c9580c3 chakra!amd64_CallFunction+0x93 27 000000eb`c42fc160 00007ffa`9c98ce3c chakra!Js::JavascriptFunction::CallFunction<1>+0x83 28 000000eb`c42fc1c0 00007ffa`9c98c406 chakra!Js::JavascriptFunction::CallRootFunctionInternal+0x104 29 000000eb`c42fc2b0 00007ffa`9c9ce4d9 chakra!Js::JavascriptFunction::CallRootFunction+0x4a 2a 000000eb`c42fc320 00007ffa`9c9928a1 chakra!ScriptSite::CallRootFunction+0xb5 2b 000000eb`c42fc3c0 00007ffa`9c98e45c chakra!ScriptSite::Execute+0x131 2c 000000eb`c42fc450 00007ffa`9d333b2d chakra!ScriptEngineBase::Execute+0xcc 2d 000000eb`c42fc4f0 00007ffa`9d333a78 edgehtml!CJScript9Holder::ExecuteCallbackDirect+0x3d 2e 000000eb`c42fc540 00007ffa`9d35ac27 edgehtml!CJScript9Holder::ExecuteCallback+0x18 2f 000000eb`c42fc580 00007ffa`9d35aa17 edgehtml!CListenerDispatch::InvokeVar+0x1fb 30 000000eb`c42fc700 00007ffa`9d33247a edgehtml!CListenerDispatch::Invoke+0xdb 31 000000eb`c42fc780 00007ffa`9d415a62 edgehtml!CEventMgr::_InvokeListeners+0x2ca 32 000000eb`c42fc8e0 00007ffa`9d290715 edgehtml!CEventMgr::_InvokeListenersOnWindow+0x66 33 000000eb`c42fc910 00007ffa`9d2901a3 edgehtml!CEventMgr::Dispatch+0x405 34 000000eb`c42fcbe0 00007ffa`9d37434a edgehtml!CEventMgr::DispatchEvent+0x73 35 000000eb`c42fcc30 00007ffa`9d3ac5a2 edgehtml!COmWindowProxy::Fire_onload+0x14e 36 000000eb`c42fcd40 00007ffa`9d3ab23e edgehtml!CMarkup::OnLoadStatusDone+0x376 37 000000eb`c42fce00 00007ffa`9d3aa72f edgehtml!CMarkup::OnLoadStatus+0x112 38 000000eb`c42fce30 00007ffa`9d328d93 edgehtml!CProgSink::DoUpdate+0x3af 39 000000eb`c42fd2c0 00007ffa`9d32a550 edgehtml!GlobalWndOnMethodCall+0x273 3a 000000eb`c42fd3c0 00007ffa`b7a31c24 edgehtml!GlobalWndProc+0x130 3b 000000eb`c42fd480 00007ffa`b7a3156c user32!UserCallWinProcCheckWow+0x274 3c 000000eb`c42fd5e0 00007ffa`9347d421 user32!DispatchMessageWorker+0x1ac 3d 000000eb`c42fd660 00007ffa`9347c9e1 EdgeContent!CBrowserTab::_TabWindowThreadProc+0x4a1 3e 000000eb`c42ff8b0 00007ffa`ad7e9586 EdgeContent!LCIETab_ThreadProc+0x2c1 3f 000000eb`c42ff9d0 00007ffa`b7978364 iertutil!_IsoThreadProc_WrapperToReleaseScope+0x16 40 000000eb`c42ffa00 00007ffa`ba0a70d1 KERNEL32!BaseThreadInitThunk+0x14 41 000000eb`c42ffa30 00000000`00000000 ntdll!RtlUserThreadStart+0x21 0:013> r rax=00000284bc287fd8 rbx=00000284bc287f90 rcx=00000000abcdbbbb rdx=0000000000000000 rsi=0000000000000017 rdi=0000000000000000 rip=00007ffa9d5f15ea rsp=000000ebc42f8da0 rbp=000000ebc42f8fb0 r8=0000000000000017 r9=000000ebc42f8e78 r10=00000fff53a47750 r11=0000000000010000 r12=0000027cb4fbcd10 r13=0000027cb4f95a78 r14=000000ebc42f8e70 r15=0000000000000000 iopl=0 nv up ei pl nz na po nc cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206 edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0x1389aa: 00007ffa`9d5f15ea 488b01 mov rax,qword ptr [rcx] ds:00000000`abcdbbbb=???????????????? 0:013> u 00007ffa`9d5f15ea edgehtml!`TextInput::TextInputLogging::Instance'::`2'::`dynamic atexit destructor for 'wrapper''+0x1389aa: 00007ffa`9d5f15ea 488b01 mov rax,qword ptr [rcx] 00007ffa`9d5f15ed 488b80d0050000 mov rax,qword ptr [rax+5D0h] 00007ffa`9d5f15f4 ff15c654ab00 call qword ptr [edgehtml!_guard_dispatch_icall_fptr (00007ffa`9e0a6ac0)] ========================================= Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/42758.zip

Products Mentioned

Configuraton 0

Microsoft>>Edge >> Version *

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_server_2016 >> Version *

References

https://www.exploit-db.com/exploits/42758/
Tags : exploit, x_refsource_EXPLOIT-DB
http://www.securitytracker.com/id/1039326
Tags : vdb-entry, x_refsource_SECTRACK
http://www.securityfocus.com/bid/100735
Tags : vdb-entry, x_refsource_BID