CVE-2021-3493: Linux Kernel Privilege Escalation Vulnerability
First published: Sat Apr 17 2021(Updated: )
Last updated 18 February 2025
Credit: security@ubuntu.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Ubuntu | <18.04 | |
| Ubuntu | >=18.04.1<20.04 | |
| Ubuntu | <20.10 | |
| Red Hat Kernel-devel | ||
| debian/linux | 5.10.223-1 5.10.234-1 6.1.123-1 6.1.128-1 6.12.12-1 6.12.16-1 |
Remedy
Apply https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52
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Reference Links
- http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html
- http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html
- http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52
- https://ubuntu.com/security/notices/USN-4917-1
- https://www.openwall.com/lists/oss-security/2021/04/16/1
- https://launchpad.net/bugs/cve/CVE-2021-3493
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52;
- https://nvd.nist.gov/vuln/detail/CVE-2021-3493
- https://security-tracker.debian.org/tracker/CVE-2021-3493
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3493
- https://ubuntu.com/security/CVE-2021-3493
Frequently Asked Questions
What is the severity of CVE-2021-3493?
CVE-2021-3493 has a high severity rating due to the potential for local privilege escalation through improper validation of file capabilities.
How do I fix CVE-2021-3493?
To fix CVE-2021-3493, upgrade the Linux kernel to versions 5.10.223-1, 5.10.226-1, 6.1.123-1, 6.1.119-1, 6.12.11-1, or 6.12.12-1.
Which versions of Ubuntu are affected by CVE-2021-3493?
CVE-2021-3493 affects Ubuntu versions ranging from 18.04 to 20.10, including specific LTS releases.
Is CVE-2021-3493 a network-related vulnerability?
No, CVE-2021-3493 is a local vulnerability that requires local access to exploit rather than being network-related.
What component of the Linux system does CVE-2021-3493 affect?
CVE-2021-3493 affects the overlayfs implementation within the Linux kernel.
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