KB4532691: Windows Server Security Update (February 2020)
Microsoft Windows Installer contains a privilege escalation vulnerability when MSI packages process symbolic links, which allows attackers to bypass access restrictions to add or remove files.
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 Software Vulnerability (CWE-59) (CWE-59) vulnerability in Microsoft Windows. An elevation of privilege vulnerability exists in the Windows Installer when MSI packages process symbolic links, aka 'Windows Installer Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-0686. 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 CatalogKB4532691Manual remediation steps
Apply the Microsoft Security Update
Microsoft has released an official security update that fixes this vulnerability.
Required KB Updates
Supersedes: KB4528760, KB4534271, KB4534273, KB4534276, KB4534283, KB4534293, KB4534297, KB4534303, KB4534306, KB4534310
Affected Products
Installation Methods
Windows Update (recommended)
Microsoft Update Catalog (manual download)
.msu installer with administrator privilegesWSUS / SCCM / Intune
Approve KB4532691 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 @('KB4532691','KB4532693','KB4537762','KB4537764','KB4537776','KB4537789','KB4537794','KB4537803','KB4537810','KB4537813','KB4537814','KB4537820','KB4537821','KB4537822') }
References
Discovery Credit
Christian Danieli (@padovah4ck)
No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.