What is CVE-2021-47559?

CVE-2021-47559 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 4.18 onward and patched in 5.10.83, 5.15.6 and 5.16. CVE-2021-47559 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47559?

CVE-2021-47559 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-2021-47559?

Yes, CVE-2021-47559 has been patched. Fixed versions include 5.10.83, 5.15.6 and 5.16. If you are running Linux kernel 4.18 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47559 actively exploited?

CVE-2021-47559 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-2021-47559

Medium

In the Linux kernel, the following vulnerability has been resolved: net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk() Coverity reports a possible NULL dereferencing problem: in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624 if (is_vlan_dev(ndev)) { Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment.

Package Linux Kernel

Published 2024-05-24

Last modified 2024-11-21

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-2021-47559 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 4.18 and later are affected. Fixed in 5.10.83, 5.15.6, 5.16 and their respective stable series.

Affected from

≥ 4.18

Fixed in

✓ 5.10.83 5.10.x ✓ 5.15.6 5.15.x ✓ 5.16

References

3 total

Kernel Git
https://git.kernel.org/stable/c/587acad41f1bc48e16f42bb2aca63bf323380be8

Patch
Kernel Git
https://git.kernel.org/stable/c/bb851d0fb02547d03cd40106b5f2391c4fed6ed1

Patch
Kernel Git
https://git.kernel.org/stable/c/c94cbd262b6aa3b54d73a1ed1f9c0d19df57f4ff

Patch

Details

CVE ID CVE-2021-47559

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-24

Modified 2024-11-21

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47559?

CVE-2021-47559 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 4.18 onward and has been patched in 5.10.83, 5.15.6 and 5.16. CVE-2021-47559 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47559?

CVE-2021-47559 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-2021-47559?

Yes. CVE-2021-47559 has been patched. Fixed versions include 5.10.83, 5.15.6 and 5.16. If you are running Linux kernel 4.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47559 actively exploited?

No. CVE-2021-47559 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.