Trusted DesignCVE-2021-43890 の詳細
CVEの情報
説明:
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.
CVE更新日: 2021-12-15 15:15:11.207000
CVSSバージョン: 3.1
CVSSスコア: 7.1
KEVの情報
KEV更新日: 2021-12-15
EPSSの情報
EPSSは脆弱性が今後30日以内に悪用される確率を予測するスコアリングシステムで、FIRST（Forum of Incident Response and Security Teams）が提供しています。
EPSSのスコアが高いということは、攻撃されるリスクが高いことを意味するので、早めの対策が必要です。
EPSSスコア: 0.129080000
EPSS更新日: 2026-01-14 00:00:00
SSVCの情報
SSVCはカーネギーメロン大学ソフトウェア工学研究所が提案する脆弱性の評価手法です。ステークホルダーごとに脆弱性対応の優先度を決定することを支援します。
本サイトでは、CVE、KEV、EPSSの内容からExploitation（悪用状況）、Technical Impact（技術的影響）、Automatable（自動攻撃の可否）を判定します。
Exploitation: active
Technical Impact: high
Automatable: False