7.1High
Linux Linux Kernel
CVE-2021-3739
A NULL pointer dereference flaw was found in the btrfs_rm_device function in fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires ‘CAP_SYS_ADMIN’. This flaw allows a local attacker to crash the system or leak kernel internal information. The highest threat from this vulnerability is to system availability.
What this means for your business
- It affects Linux Kernel. It matters if your company, or a supplier that handles your data, runs it.
- Code showing how to exploit it has been published, but real attacks have not been confirmed.
- An attacker can use it only with access to the machine itself, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.6% chance of attack attempts being seen in the next 30 days, ranking above 47% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Linux Kernel, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 7.1 (v3.1)
- Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H- Weakness
- CWE-476
- Assigned by
- secalert@redhat.com
Dates
- Published
- 2022-03-10
- Last modified
- 2026-09-01
- Sources
- NVD
Affected products
- Linux Linux Kernel4.20 - 5.4.144, 5.5 - 5.10.62, 5.11 - 5.13.14, 5.14 - 5.14.1
- Fedoraproject Fedora34
- Netapp H300s Firmwareall versions
- Netapp H300sall versions
- Netapp H500s Firmwareall versions
- Netapp H500sall versions
- Netapp H700s Firmwareall versions
- Netapp H700sall versions
- Netapp H300e Firmwareall versions
- Netapp H300eall versions
- Netapp H500e Firmwareall versions
- Netapp H500eall versions
As listed in the NVD configuration data. Not a statement about your estate.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1997958
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
- https://github.com/torvalds/linux/commit/e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
- https://security.netapp.com/advisory/ntap-20220407-0006/
- https://ubuntu.com/security/CVE-2021-3739
- https://www.openwall.com/lists/oss-security/2021/08/25/3
- https://bugzilla.redhat.com/show_bug.cgi?id=1997958
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
- https://github.com/torvalds/linux/commit/e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
- https://security.netapp.com/advisory/ntap-20220407-0006/
- https://ubuntu.com/security/CVE-2021-3739
- https://www.openwall.com/lists/oss-security/2021/08/25/3