CVE-2021-3493 Linux Kernel: login or permission bypass
In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.
Confirmed exploited by CISA on · US federal patch deadline Nov 10, 2022
What to do
- Install Linux's security update for Kernel. 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. This one is aimed at devices or apps of the kind people own.
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
- Linux Kernel Privilege Escalation Vulnerability
- Product
- Linux Kernel
- CISA description
- The overlayfs stacking file system in Linux kernel does not properly validate the application of file capabilities against user namespaces, which could lead to privilege escalation.
- Type of flaw
- Login or permission bypass (CWE-862)
- Confirmed exploited
- Oct 20, 2022
- US federal patch deadline
- Nov 10, 2022
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Answering about CVE-2021-3493 ·
Questions about CVE-2021-3493
Is CVE-2021-3493 being exploited?
Yes. CISA added CVE-2021-3493 to its Known Exploited Vulnerabilities catalog on Oct 20, 2022, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2021-3493?
Install Linux's security update for Kernel. 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-2021-3493?
Only if you use Linux Kernel. This one is aimed at devices or apps of the kind people own.