What is CVE-2021-47217?

CVE-2021-47217 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a NULL Pointer Dereference flaw (CWE-476), affecting Linux kernel versions from 4.16 onward and patched in 4.19.218, 5.4.162, 5.10.82 and others. CVE-2021-47217 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47217?

CVE-2021-47217 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47217?

Yes, CVE-2021-47217 has been patched. Fixed versions include 4.19.218, 5.4.162, 5.10.82 and others. If you are running Linux kernel 4.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47217 actively exploited?

CVE-2021-47217 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is NULL Pointer Dereference (CWE-476)?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/476.html

CVE-2021-47217

Medium

In the Linux kernel, the following vulnerability has been resolved: x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails Check for a valid hv_vp_index array prior to derefencing hv_vp_index when setting Hyper-V's TSC change callback. If Hyper-V setup failed in hyperv_init(), the kernel will still report that it's running under Hyper-V, but will have silently disabled nearly all functionality. BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc2+ #75 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:set_hv_tscchange_cb+0x15/0xa0 Code: <8b> 04 82 8b 15 12 17 85 01 48 c1 e0 20 48 0d ee 00 01 00 f6 c6 08 ... Call Trace: kvm_arch_init+0x17c/0x280 kvm_init+0x31/0x330 vmx_init+0xba/0x13a do_one_initcall+0x41/0x1c0 kernel_init_freeable+0x1f2/0x23b kernel_init+0x16/0x120 ret_from_fork+0x22/0x30

Package Linux Kernel

Published 2024-04-10

Last modified 2025-01-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2021-47217 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.16 and later are affected. Fixed in 4.19.218, 5.4.162, 5.10.82, 5.15.5, 5.16 and their respective stable series.

Affected from

≥ 4.16

Fixed in

✓ 4.19.218 4.19.x ✓ 5.4.162 5.4.x ✓ 5.10.82 5.10.x ✓ 5.15.5 5.15.x ✓ 5.16

References

5 total

Kernel Git
https://git.kernel.org/stable/c/8823ea27fff6084bbb4bc71d15378fae0220b1d8

Patch
Kernel Git
https://git.kernel.org/stable/c/9c177eee116cf888276d3748cb176e72562cfd5c

Patch
Kernel Git
https://git.kernel.org/stable/c/b0e44dfb4e4c699cca33ede431b8d127e6e8d661

Patch
Kernel Git
https://git.kernel.org/stable/c/b20ec58f8a6f4fef32cc71480ddf824584e24743

Patch
Kernel Git
https://git.kernel.org/stable/c/daf972118c517b91f74ff1731417feb4270625a4

Patch

Details

CVE ID CVE-2021-47217

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-04-10

Modified 2025-01-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47217?

CVE-2021-47217 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 4.16 onward and has been patched in 4.19.218, 5.4.162, 5.10.82 and others. CVE-2021-47217 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47217?

CVE-2021-47217 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47217?

Yes. CVE-2021-47217 has been patched. Fixed versions include 4.19.218, 5.4.162, 5.10.82 and others. If you are running Linux kernel 4.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47217 actively exploited?

No. CVE-2021-47217 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.