What is CVE-2021-47593?

CVE-2021-47593 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 5.6 onward and patched in 5.10.88, 5.15.11 and 5.16. CVE-2021-47593 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47593?

CVE-2021-47593 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-2021-47593?

Yes, CVE-2021-47593 has been patched. Fixed versions include 5.10.88, 5.15.11 and 5.16. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47593 actively exploited?

CVE-2021-47593 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-2021-47593

Medium

In the Linux kernel, the following vulnerability has been resolved: mptcp: clear 'kern' flag from fallback sockets The mptcp ULP extension relies on sk->sk_sock_kern being set correctly: It prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, "mptcp", 6); from working for plain tcp sockets (any userspace-exposed socket). But in case of fallback, accept() can return a plain tcp sk. In such case, sk is still tagged as 'kernel' and setsockopt will work. This will crash the kernel, The subflow extension has a NULL ctx->conn mptcp socket: BUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0 Call Trace: tcp_data_ready+0xf8/0x370 [..]

Package Linux Kernel

Published 2024-06-19

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-2021-47593 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 5.6 and later are affected. Fixed in 5.10.88, 5.15.11, 5.16 and their respective stable series.

Affected from

≥ 5.6

Fixed in

✓ 5.10.88 5.10.x ✓ 5.15.11 5.15.x ✓ 5.16

References

3 total

Kernel Git
https://git.kernel.org/stable/c/451f1eded7f56e93aaf52eb547ba97742d9c0e97

Patch
Kernel Git
https://git.kernel.org/stable/c/c26ac0ea3a91c210cf90452e625dc441adf3e549

Patch
Kernel Git
https://git.kernel.org/stable/c/d6692b3b97bdc165d150f4c1505751a323a80717

Patch

Details

CVE ID CVE-2021-47593

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-06-19

Modified 2024-11-21

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47593?

CVE-2021-47593 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 5.6 onward and has been patched in 5.10.88, 5.15.11 and 5.16. CVE-2021-47593 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47593?

CVE-2021-47593 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-2021-47593?

Yes. CVE-2021-47593 has been patched. Fixed versions include 5.10.88, 5.15.11 and 5.16. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47593 actively exploited?

No. CVE-2021-47593 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.