CVE-2018-8389 — Scripting Engine Memory Corruption Vulnerability

Executive Summary

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. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the scripting engine handles objects in memory.

Overview

7.5

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

More Likely

MS Exploit Likelihood

Category Remote Code Execution

Released Aug 14 2018

Last Updated Aug 14 2018

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

CVSS Vector

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

None

USER INTERACTION

Required

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.7

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

14 affected products

Product	KB Article	Severity	Impact	Restart Required
Internet Explorer 10 on Windows Server 2012 4343901 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338830 4339093 Base: 6.4 Temporal: 5.8 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows 10 for 32-bit Systems	`4343892 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 for x64-based Systems	`4343892 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems	`4343887 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems	`4343887 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1703 for 32-bit Systems	`4343885 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1703 for x64-based Systems	`4343885 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1709 for 32-bit Systems	`4343897 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1709 for x64-based Systems	`4343897 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1803 for 32-bit Systems	`4343909 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1803 for x64-based Systems	`4343909 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows 7 for 32-bit Systems Service Pack 1 4343900 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338818 4339093 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows 7 for x64-based Systems Service Pack 1 4343900 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338818 4339093 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows 8.1 for 32-bit systems 4343898 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338815 4339093 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows 8.1 for x64-based systems 4343898 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338815 4339093 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows RT 8.1	`4343898 (Monthly Rollup)`	Important	Remote Code Execution	Yes
Internet Explorer 11 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 4343900 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338818 4339093 Base: 6.4 Temporal: 5.8 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows Server 2012 R2 4343898 (Monthly Rollup) 4343205 (IE Cumulative) Important Remote Code Execution 4338815 4339093 Base: 6.4 Temporal: 5.8 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows Server 2016	`4343887 (Security Update)`	Important	Remote Code Execution	Yes
Internet Explorer 9 on Windows Server 2008 for 32-bit Systems Service Pack 2	`4343205 (IE Cumulative)`	Important	Remote Code Execution	Yes
Internet Explorer 9 on Windows Server 2008 for x64-based Systems Service Pack 2	`4343205 (IE Cumulative)`	Important	Remote Code Execution	Yes

Patches

7 patches

Article	Type	Restart
`4343892`	Security Update	Yes
`4343887`	Security Update	Yes
`4343885`	Security Update	Yes
`4343897`	Security Update	Yes
`4343909`	Security Update	Yes
`4343898`	Monthly Rollup	Yes
`4343205`	IE Cumulative	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Sudhakar Verma and Ashfaq Ansari - Project Srishti working with iDefense Labs

References

MSRC Advisory MITRE NVD