CVE-2021-43890

Katalog CVE

CVSS 7.1 · High KEV · sudah dieksploitasi Dipakai ransomware EPSS 11,3%

Kerentanan pada microsoft app installer. Skor CVSS 3.1 7.1 (High) menurut NVD. Masuk katalog KEV CISA pada 15 Desember 2021, artinya sudah terbukti dieksploitasi. Tercatat dipakai dalam kampanye ransomware.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD

15 Desember 2021

Terakhir diubah

6 Agustus 2026

Status NVD

Analyzed

CVSS 3.1

7.1 (High), sumber NVD
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H · uraikan di kalkulator

EPSS (30 hari)

11,3% peluang dieksploitasi; lebih tinggi dari 95,8% CVE lain

Known Exploited Vulnerabilities (CISA)

Nama

Microsoft Windows AppX Installer Spoofing Vulnerability

Masuk KEV

15 Desember 2021

Tenggat CISA

29 Desember 2021 (untuk instansi federal AS)

Ransomware

Tercatat dipakai dalam kampanye ransomware

Tindakan wajib

Apply updates per vendor instructions.

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43890 patch · advisory vendor
• https://www.microsoft.com/en-us/security/blog/2023/12/28/financially-motivated-threat-actors-misusing-app-inst... exploit · advisory vendor
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-43890 pemerintah AS
• https://thehackernews.com/2023/12/microsoft-disables-msix-app-installer.html press/media coverage · advisory pihak ketiga
• https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-msix-protocol-handler-abused-in-malware-att... press/media coverage · advisory pihak ketiga
• https://github.com/ChrisTitusTech/winutil/pull/26 issue tracking