CVE-2018-8403 — Microsoft Browser Memory Corruption Vulnerability

Executive Summary

A remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory. The vulnerability could corrupt memory in a way that could allow an attacker to 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, the attacker 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. An attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft browsers, and then convince a user to view the website. The attacker could also take advantage of compromised websites, or websites that accept or host user-provided content or advertisements, by adding specially crafted content that could exploit the vulnerability. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically via an enticement in email or instant message, or by getting them to open an email attachment. The security update addresses the vulnerability by modifying how Microsoft browsers handle objects in memory.

Overview

4.2

CVSS MEDIUM

Moderate

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

Low

INTEGRITY

Low

AVAILABILITY

None

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 3.8

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

19 affected products

Product	KB Article	Severity	Impact	Restart Required
Internet Explorer 10 on Windows Server 2012 4343901 (Monthly Rollup) 4343205 (IE Cumulative) Moderate Remote Code Execution 4338830 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows 10 for 32-bit Systems	`4343892 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 for x64-based Systems	`4343892 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems	`4343887 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems	`4343887 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1703 for 32-bit Systems	`4343885 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1703 for x64-based Systems	`4343885 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1709 for 32-bit Systems	`4343897 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1709 for x64-based Systems	`4343897 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1803 for 32-bit Systems	`4343909 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 10 Version 1803 for x64-based Systems	`4343909 (Security Update)`	Critical	Remote Code Execution	Yes
Internet Explorer 11 on Windows 7 for 32-bit Systems Service Pack 1 4343900 (Monthly Rollup) 4343205 (IE Cumulative) Critical Remote Code Execution 4338818 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/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) Critical Remote Code Execution 4338818 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/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) Critical Remote Code Execution 4338815 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/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) Critical Remote Code Execution 4338815 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows RT 8.1	`4343898 (Monthly Rollup)`	Critical	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) Moderate Remote Code Execution 4338818 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows Server 2012 R2 4343898 (Monthly Rollup) 4343205 (IE Cumulative) Moderate Remote Code Execution 4338815 4339093 Base: 4.2 Temporal: 3.8 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C Yes None Internet Explorer 11 on Windows Server 2016	`4343887 (Security Update)`	Moderate	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 for 32-bit Systems	`4343892 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 for x64-based Systems	`4343892 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for 32-bit Systems	`4343887 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for x64-based Systems	`4343887 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1703 for 32-bit Systems	`4343885 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1703 for x64-based Systems	`4343885 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2016	`4343887 (Security Update)`	Moderate	Remote Code Execution	Yes

Patches

6 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

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

Jihui Lu of Tencent KeenLab

References

MSRC Advisory MITRE NVD