KB4565349: Windows Server Security Update (August 2020)
Microsoft Internet Explorer contains a memory corruption vulnerability which can allow for remote code execution in the context of the current user.
A local attacker, with a low-privilege account, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2022-05-03 under CISA BOD 22-01.
This is a Out-of-bounds Write (CWE-787) vulnerability in Microsoft Internet Explorer. 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. Exploitation requires local access, low attack complexity, a low-privilege authenticated account, and no user interaction required.
Probably yes if any of these apply:
CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2021-11-03 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2022-05-03.
Manual download
For air-gapped servers or out-of-band deployment. Microsoft Update Catalog returns every OS-version variant of this update.
↗ Microsoft Update CatalogKB4565349Manual remediation steps
Apply the Microsoft Security Update
Microsoft has released an official security update that fixes this vulnerability.
Required KB Updates
Supersedes: KB4558998, KB4565479, KB4565483, KB4565489, KB4565503, KB4565508, KB4565511, KB4565513, KB4565524, KB4565537, KB4565541
Affected Products
Installation Methods
Windows Update (recommended)
Microsoft Update Catalog (manual download)
.msu installer with administrator privilegesWSUS / SCCM / Intune
Approve KB4565349 for the affected products in your update management console.
Microsoft Download Center Links
Verification
Confirm the update is installed:
Get-HotFix | Where-Object { $_.HotFixID -in @('KB4565349','KB4565351','KB4566782','KB4571687','KB4571692','KB4571694','KB4571703','KB4571709','KB4571729','KB4571736','KB4571741') }
References
Discovery Credit
Boris Larin (Oct0xor) of Kaspersky Lab
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