{"answers":{"affected":"It affects 17 products.","exploited":"Yes. Attackers have exploited CVE-2021-40444 in the wild since at least 3 Nov 2021, including in ransomware campaigns.","fix":"Apply the vendor's patch. US federal agencies must fix it by 17 Nov 2021.","what":"CVE-2021-40444 is a high-severity path traversal vulnerability in Microsoft Windows 10 1507, published on 15 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2021-40444 and fix it if it is affected.\n\nWhat it is: CVE-2021-40444 is a high-severity path traversal vulnerability in Microsoft Windows 10 1507, published on 15 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: Yes. Attackers have exploited CVE-2021-40444 in the wild since at least 3 Nov 2021, including in ransomware campaigns.\n\nAffected product: Microsoft Windows 10 1507. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-40444/ (Markdown: https://insights.sbomify.com/CVE-2021-40444/index.md)","id":"CVE-2021-40444","markdown":"https://insights.sbomify.com/CVE-2021-40444/index.md","name":"CVE-2021-40444","record":{"aliases":["GHSA-2h32-fhf6-xhh5","openSUSE-SU-2024:13674-1"],"analysis":{"component_type":"operating_system","fix_type":"patch","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Windows MSHTML","requires_auth":"none","summary":"Attackers can execute arbitrary code by tricking users into opening malicious Office documents that exploit a path traversal flaw in the MSHTML rendering engine.","user_interaction":"required","vuln_class":"path_traversal"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"microsoft","cpe":[{"product":"windows_10_1507","vendor":"microsoft"},{"product":"windows_10_1607","vendor":"microsoft"},{"product":"windows_10_1809","vendor":"microsoft"},{"product":"windows_10_1909","vendor":"microsoft"},{"product":"windows_10_2004","vendor":"microsoft"},{"product":"windows_10_20h2","vendor":"microsoft"},{"product":"windows_10_21h1","vendor":"microsoft"},{"product":"windows_7","vendor":"microsoft"},{"product":"windows_8.1","vendor":"microsoft"},{"product":"windows_rt_8.1","vendor":"microsoft"},{"product":"windows_server_2004","vendor":"microsoft"},{"product":"windows_server_2008","vendor":"microsoft"},{"product":"windows_server_2012","vendor":"microsoft"},{"product":"windows_server_2016","vendor":"microsoft"},{"product":"windows_server_2019","vendor":"microsoft"},{"product":"windows_server_2022","vendor":"microsoft"},{"product":"windows_server_20h2","vendor":"microsoft"}],"cvss":{"score":8.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:C","version":"3.1"},"cwes":[{"id":"CWE-22","name":"Improper Limitation of a Pathname to a Restricted Directory"}],"description":"Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. Microsoft is aware of targeted attacks that attempt to exploit this vulnerability by using specially-crafted Microsoft Office documents.\nAn attacker could craft a malicious ActiveX control to be used by a Microsoft Office document that hosts the browser rendering engine. The attacker would then have to convince the user to open the malicious document. 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.\nMicrosoft Defender Antivirus and Microsoft Defender for Endpoint both provide detection and protections for the known vulnerability. Customers should keep antimalware products up to date. Customers who utilize automatic updates do not need to take additional action. Enterprise customers who manage updates should select the detection build 1.349.22.0 or newer and deploy it across their environments. Microsoft Defender for Endpoint alerts will be displayed as: “Suspicious Cpl File Execution”.\nUpon completion of this investigation, Microsoft will take the appropriate action to help protect our customers. This may include providing a security update through our monthly release process or providing an out-of-cycle security update, depending on customer needs.\nPlease see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability.\nUPDATE September 14, 2021: Microsoft has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. Please see the FAQ for important information about which updates are applicable to your system.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2021-09-08","github_poc":35,"max_poc_stars":1850,"metasploit":1,"nuclei":0,"refs":[{"date":"2021-09-10T16:55:53Z","kind":"github_poc","ref":"https://github.com/lockedbyte/CVE-2021-40444","stars":1850,"title":"CVE-2021-40444 PoC"},{"date":"2021-09-15T22:34:35Z","kind":"github_poc","ref":"https://github.com/klezVirus/CVE-2021-40444","stars":838,"title":"CVE-2021-40444 - Fully Weaponized Microsoft Office Word RCE Exploit"},{"date":"2021-09-12T18:05:53Z","kind":"github_poc","ref":"https://github.com/aslitsecurity/CVE-2021-40444_builders","stars":175,"title":"This repo contain builders of cab file, html file, and docx file for CVE-2021-40444 exploit"},{"date":"2021-09-19T19:46:28Z","kind":"github_poc","ref":"https://github.com/Edubr2020/CVE-2021-40444--CABless","stars":105,"title":"Modified code so that we don´t need to rely on CAB archives"},{"date":"2021-12-19T08:16:07Z","kind":"github_poc","ref":"https://github.com/34zY/Microsoft-Office-Word-MSHTML-Remote-Code-Execution-Exploit","stars":65,"title":"CVE-2021-40444"},{"date":"2021-09-14T17:10:48Z","kind":"github_poc","ref":"https://github.com/k8gege/CVE-2021-40444","stars":21,"title":null},{"date":"2021-09-08T08:32:40Z","kind":"github_poc","ref":"https://github.com/ozergoker/CVE-2021-40444","stars":18,"title":"Microsoft MSHTML Remote Code Execution Vulnerability CVE-2021-40444"},{"date":"2021-09-09T03:15:57Z","kind":"github_poc","ref":"https://github.com/rfcxv/CVE-2021-40444-POC","stars":18,"title":null}],"tier":"exploited"},"has_fix":true,"headline":"Microsoft MSHTML Remote Code Execution","id":"CVE-2021-40444","indexable":true,"kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","knownRansomwareCampaignUse":"Known","product":"MSHTML","requiredAction":"Apply updates per vendor instructions.","vendorProject":"Microsoft","vulnerabilityName":"Microsoft MSHTML Remote Code Execution Vulnerability"},"kind":"cve","links":{"ecosystem":null,"product":"microsoft:windows_10_1507","products":["microsoft:windows_10_1507","microsoft:windows_10_1607","microsoft:windows_10_1809","microsoft:windows_10_20h2","microsoft:windows_10_21h1","microsoft:windows_7","microsoft:windows_8.1","microsoft:windows_rt_8.1","microsoft:windows_server_2008","microsoft:windows_server_2012","microsoft:windows_server_2016","microsoft:windows_server_2019","microsoft:windows_server_2022","microsoft:windows_server_20h2"],"type":"path_traversal","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Windows Print Spooler Elevation of Privilege Vulnerability","id":"CVE-2021-40447"},"packages":[],"prev":{"headline":"Windows Common Log File System Driver Elevation of Privilege Vulnerability","id":"CVE-2021-40443"},"products":["Windows 10 Version 1507","Windows 10 Version 1607","Windows 10 Version 1809","Windows 10 Version 1909","Windows 10 Version 2004","Windows 10 Version 20H2","Windows 10 Version 21H1","Windows 7","Windows 7 Service Pack 1","Windows 8.1","Windows Server 2008 R2 Service Pack 1","Windows Server 2008 R2 Service Pack 1 (Server Core installation)","Windows Server 2008 Service Pack 2","Windows Server 2008 Service Pack 2 (Server Core installation)","Windows Server 2012","Windows Server 2012 (Server Core installation)","Windows Server 2012 R2","Windows Server 2012 R2 (Server Core installation)","Windows Server 2016","Windows Server 2016 (Server Core installation)","Windows Server 2019","Windows Server 2019 (Server Core installation)","Windows Server 2022","Windows Server version 2004","Windows Server version 20H2"],"published":"2021-09-15","related":[{"cvss_score":9.8,"headline":"Microsoft Windows Search Remote Code Execution","id":"CVE-2017-8543","kev_date_added":"2022-05-24","published":"2017-06-15"},{"cvss_score":8.8,"headline":"Microsoft Windows External Control of File Name or Path","id":"CVE-2025-33053","kev_date_added":"2025-06-10","published":"2025-06-10"},{"cvss_score":8.8,"headline":"Microsoft Windows SMB Client Improper Access Control","id":"CVE-2025-33073","kev_date_added":"2025-10-20","published":"2025-06-10"},{"cvss_score":8.8,"headline":"Microsoft Windows Task Scheduler Privilege Escalation","id":"CVE-2024-49039","kev_date_added":"2024-11-12","published":"2024-11-12"},{"cvss_score":8.8,"headline":"Microsoft Windows MSHTML Platform Spoofing","id":"CVE-2024-43461","kev_date_added":"2024-09-16","published":"2024-09-10"},{"cvss_score":8.8,"headline":"Microsoft Windows MSHTML Platform Security Feature Bypass","id":"CVE-2024-30040","kev_date_added":"2024-05-14","published":"2024-05-14"},{"cvss_score":8.8,"headline":"Microsoft Windows SmartScreen Security Feature Bypass","id":"CVE-2023-36025","kev_date_added":"2023-11-14","published":"2023-11-14"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"open","licence":"CC0 1.0","name":"CISA KEV"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"active","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-08-10","vendors":["Microsoft"]},"summary":"Attackers can execute arbitrary code by tricking users into opening malicious Office documents that exploit a path traversal flaw in the MSHTML rendering engine.","url":"https://insights.sbomify.com/CVE-2021-40444/"}