CVE-2021-38646 Microsoft Office: command or code injection
In plain words: The program treats text it receives as instructions instead of plain data. The attacker can run commands on the machine — often the whole device is taken over.
Confirmed exploited by CISA on · US federal patch deadline Apr 18, 2022
What to do
- Install Microsoft's security update for Office. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Turn on automatic updates for the operating system and for Office, PDF and archive apps.
- Be careful with unexpected attachments — documents, .zip/.rar files and shortcuts are common bait.
- Use a normal (non-admin) account day to day and keep built-in protection like Microsoft Defender on.
Who is affected
Could reach you. Used in ransomware, which spreads to ordinary people and small businesses.
What's at risk: Your files, saved passwords and accounts. Many of these let a program that is already running gain full administrator control.
The details
- Official name
- Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
- Product
- Microsoft Office
- CISA description
- Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
- Type of flaw
- Command or code injection
- Confirmed exploited
- Mar 28, 2022 — known to be used in ransomware attacks
- US federal patch deadline
- Apr 18, 2022
Ask Cleus about it
Ask about a vulnerability, an update, a weird message, or the news. Plain-word answers, free, no account.
Answering about CVE-2021-38646 ·
Questions about CVE-2021-38646
Is CVE-2021-38646 being exploited?
Yes. CISA added CVE-2021-38646 to its Known Exploited Vulnerabilities catalog on Mar 28, 2022, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2021-38646?
Install Microsoft's security update for Office. If no update exists, follow the vendor's workaround or stop using the product until one ships. Turn on automatic updates for the operating system and for Office, PDF and archive apps.
Am I affected by CVE-2021-38646?
Only if you use Microsoft Office. Used in ransomware, which spreads to ordinary people and small businesses.