Microsoft Internet Explorer 9/11 Scripting Engine jscript!JSONStringifyObject memory corruption

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.8	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Microsoft Internet Explorer 9/11 and classified as critical. Impacted is the function jscript!JSONStringifyObject of the component Scripting Engine. The manipulation results in memory corruption. This vulnerability is identified as CVE-2017-11793. The attack can be executed remotely. Additionally, an exploit exists. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Microsoft Internet Explorer 9/11 (Web Browser). Affected is the function jscript!JSONStringifyObject of the component Scripting Engine. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability.

The bug was discovered 10/10/2017. The weakness was released 10/10/2017 by Hui Gao (ERNE) with Application Security as KB4040685 as confirmed security update guide (Website). The advisory is available at portal.msrc.microsoft.com. This vulnerability is traded as CVE-2017-11793 since 07/31/2017. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. Technical details and a public exploit are known. The advisory points out:

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

A public exploit has been developed by Google Security Research and been published 3 months after the advisory. The exploit is shared for download at exploit-db.com. It is declared as proof-of-concept. As 0-day the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 103745 (KB4041676: Windows 10 Version 1703 October 2017 Cumulative Update (KRACK)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows : Microsoft Bulletins and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 100320 (Microsoft Internet Explorer Security Update for October 2017). The code used by the exploit is:

<!-- saved from url=(0014)about:internet -->
<meta http-equiv="X-UA-Compatible" content="IE=8"></meta>
<script language="Jscript.Encode">
 
var o1 = {toJSON:function(){
  alert('o1');
  return [o2];
}}
 
var o2 = {toJSON:function(){
  alert('o2');
  CollectGarbage();
  return 'x';
}}
 
JSON.stringify(o1);
 
</script>

Applying the patch KB4040685 is able to eliminate this problem. The bugfix is ready for download at catalog.update.microsoft.com. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (43368), Tenable (103745) and SecurityFocus (BID 101141†). Entries connected to this vulnerability are available at VDB-107699, VDB-107700, VDB-107701 and VDB-107702. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Web Browser

Vendor

Microsoft

Name

Internet Explorer

Version

License

commercial

Support

end of life

Website

Vendor: https://www.microsoft.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.8

VulDB Base Score: 4.3
VulDB Temp Score: 3.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 3.1
Vendor Vector (Microsoft): 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Google Security Research
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 103745
Nessus Name: KB4041676: Windows 10 Version 1703 October 2017 Cumulative Update (KRACK)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 802286
OpenVAS Name: Microsoft Internet Explorer Multiple Vulnerabilities (KB4040685)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Exploit Delay Time: 🔍

Patch: KB4040685

Timelineinfo

07/31/2017 🔍
10/10/2017 +71 days 🔍
10/10/2017 +0 days 🔍
10/10/2017 +0 days 🔍
10/10/2017 +0 days 🔍
10/10/2017 +0 days 🔍
10/11/2017 +1 days 🔍
10/13/2017 +2 days 🔍
12/19/2017 +67 days 🔍
12/19/2017 +0 days 🔍
12/20/2025 +2923 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: KB4040685
Researcher: Hui Gao (ERNE)
Organization: Application Security
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-11793 (🔍)
GCVE (CVE): GCVE-0-2017-11793
GCVE (VulDB): GCVE-100-107706

OVAL: 🔍

SecurityFocus: 101141 - Microsoft Internet Explorer CVE-2017-11793 Remote Memory Corruption Vulnerability
SecurityTracker: 1039532

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 10/11/2017 23:38
Updated: 12/20/2025 06:03
Changes: 10/11/2017 23:38 (104), 12/16/2019 10:46 (4), 01/16/2021 10:12 (3), 12/20/2025 06:03 (15)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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