CVE-2021-43890

תיאור (מקור, אנגלית)

We have investigated reports of a spoofing vulnerability in AppX installer that affects Microsoft Windows. Microsoft is aware of attacks that attempt to exploit this vulnerability by using specially crafted packages that include the malware family known as Emotet/Trickbot/Bazaloader. An attacker could craft a malicious attachment to be used in phishing campaigns. The attacker would then have to convince the user to open the specially crafted attachment. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Please see the Security Updates table for the link to the updated app. Alternatively you can download and install the Installer using the links provided in the FAQ section. Please see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability. December 27 2023 Update: In recent months, Microsoft Threat Intelligence has seen an increase in activity from threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the ms-appinstaller URI scheme. To address this increase in activity, we have updated the App Installer to disable the ms-appinstaller protocol by default and recommend other potential mitigations.

מדדים

CVSS 3.1

7.1 (HIGH) מקור הציון: NVD CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H

EPSS — סבירות ניצול

10% (אחוזון 100) נכון ל-25/7/2026

מוצרים מושפעים

microsoft: app installer; microsoft: windows 10 1809; microsoft: windows 10 1903; microsoft: windows 10 1909; microsoft: windows 10 2004; microsoft: windows 10 20h2; microsoft: windows 10 21h1; microsoft: windows 10 21h2; microsoft: windows 11 21h2; microsoft: windows 10 1507; microsoft: windows 10 1709; microsoft: windows 10 1803

קישורים

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43‮… PatchVendor Advisory
• https://www.microsoft.com/en-us/security/blog/2023/12/28/financially-motivated‮… ExploitVendor Advisory
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43‮… PatchVendor Advisory
• https://www.microsoft.com/en-us/security/blog/2023/12/28/financially-motivated‮… ExploitVendor Advisory
• https://github.com/ChrisTitusTech/winutil/pull/26 Issue Tracking
• https://thehackernews.com/2023/12/microsoft-disables-msix-app-installer.html Press/Media CoverageThird Party Advisory
• https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-msix-protoc‮… Press/Media CoverageThird Party Advisory
• https://github.com/ChrisTitusTech/winutil/pull/26 Issue Tracking
• https://thehackernews.com/2023/12/microsoft-disables-msix-app-installer.html Press/Media CoverageThird Party Advisory
• https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-msix-protoc‮… Press/Media CoverageThird Party Advisory