Microsoft Edge Scripting Engine GetPropertyBuiltIns memory corruption

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5.4$0-$5k0.00

A vulnerability was found in Microsoft Edge (Web Browser) (version now known) and classified as critical. This issue affects the function JavascriptGeneratorFunction::GetPropertyBuiltIns of the component Scripting Engine. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

ChakraCore and Microsoft Edge in Windows 10 1511, 1607, 1703, 1709, and Windows Server 2016 allows an attacker to gain the same user rights as the current user, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-11886, CVE-2017-11889, CVE-2017-11890, CVE-2017-11893, CVE-2017-11894, CVE-2017-11895, CVE-2017-11901, CVE-2017-11903, CVE-2017-11905, CVE-2017-11905, CVE-2017-11907, CVE-2017-11908, CVE-2017-11909, CVE-2017-11910, CVE-2017-11911, CVE-2017-11912, CVE-2017-11913, CVE-2017-11916, CVE-2017-11918, and CVE-2017-11930.

The bug was discovered 12/12/2017. The weakness was presented 12/12/2017 by lokihardt with Google Project Zero as confirmed security update guide (Website). It is possible to read the advisory at portal.msrc.microsoft.com. The identification of this vulnerability is CVE-2017-11914 since 07/31/2017. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details as well as 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 Microsoft Edge. 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 2 months after the advisory. The exploit is available at exploit-db.com. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 105180 (KB4053579: Windows 10 Version 1607 and Windows Server 2016 December 2017 Security Update), 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 91416 (Microsoft Edge Security Update for December 2017). The code used by the exploit is:

function* f() {
}
 
let g;
f.__defineGetter__('length', function () {
    g = this;  // g == "scriptFunction"
});
 
 
f.length;
 
g.call(0x1234, 0x5678);  // type confusion

Applying a patch 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 Tenable (105180) and Exploit-DB (43713). See 110525, 110526, 110528 and 110531 for similar entries.

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CPE 2.3info

CPE 2.2info

CVSSv4info

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CVSSv3info

VulDB Meta Base Score: 6.0
VulDB Meta Temp Score: 5.8

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 4.2
Vendor Vector (Microsoft): 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Memory corruption
CWE: CWE-119
ATT&CK: Unknown

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: 🔍

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Nessus ID: 105180
Nessus Name: KB4053579: Windows 10 Version 1607 and Windows Server 2016 December 2017 Security Update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 56516
OpenVAS Name: Microsoft Windows Multiple Vulnerabilities (KB4054517)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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Countermeasuresinfo

Recommended: Patch
Status: 🔍

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Patch: catalog.update.microsoft.com

Timelineinfo

07/31/2017 🔍
12/12/2017 +134 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/13/2017 +1 days 🔍
01/17/2018 +35 days 🔍
01/17/2018 +0 days 🔍
01/27/2021 +1106 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: portal.msrc.microsoft.com
Researcher: Lokihardt (lokihardt)
Organization: Google Project Zero
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-11914 (🔍)
OVAL: 🔍

SecurityTracker: 1039990
SecurityFocus: 102088 - Microsoft Edge Scripting Engine CVE-2017-11914 Remote Memory Corruption Vulnerability

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

Entryinfo

Created: 12/13/2017 07:56
Updated: 01/27/2021 07:51
Changes: 12/13/2017 07:56 (100), 12/24/2019 13:55 (3), 01/27/2021 07:48 (2), 01/27/2021 07:51 (1)
Complete: 🔍

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