What is CVE-2021-47243?

CVE-2021-47243 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10, classified as a Out-of-bounds Read flaw (CWE-125), affecting Linux kernel versions from 4.19 onward and patched in 4.19.196, 5.4.128, 5.10.46 and others. CVE-2021-47243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47243?

CVE-2021-47243 has a CVSS score of 7.1 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Is there a patch available for CVE-2021-47243?

Yes, CVE-2021-47243 has been patched. Fixed versions include 4.19.196, 5.4.128, 5.10.46 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47243 actively exploited?

CVE-2021-47243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/125.html

CVE-2021-47243

High

In the Linux kernel, the following vulnerability has been resolved: sch_cake: Fix out of bounds when parsing TCP options and header The TCP option parser in cake qdisc (cake_get_tcpopt and cake_tcph_may_drop) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options."). v2 changes: Added doff validation in cake_get_tcphdr to avoid parsing garbage as TCP header. Although it wasn't strictly an out-of-bounds access (memory was allocated), garbage values could be read where CAKE expected the TCP header if doff was smaller than 5.

Package Linux Kernel

Published 2024-05-21

Last modified 2024-12-30

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.1

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-125

CVE-2021-47243 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.19 and later are affected. Fixed in 4.19.196, 5.4.128, 5.10.46, 5.12.13, 5.13 and their respective stable series.

Affected from

≥ 4.19

Fixed in

✓ 4.19.196 4.19.x ✓ 5.4.128 5.4.x ✓ 5.10.46 5.10.x ✓ 5.12.13 5.12.x ✓ 5.13

References

5 total

Kernel Git
https://git.kernel.org/stable/c/3371392c60e2685af30bd4547badd880f5df2b3f

Patch
Kernel Git
https://git.kernel.org/stable/c/3b491dd593d582ceeb27aa617600712a6bd14246

Patch
Kernel Git
https://git.kernel.org/stable/c/4cefa061fc63f4d2dff5ab4083f43857cd7a2335

Patch
Kernel Git
https://git.kernel.org/stable/c/595897ef118d6fe66690c4fc5b572028c9da95b7

Patch
Kernel Git
https://git.kernel.org/stable/c/ba91c49dedbde758ba0b72f57ac90b06ddf8e548

Patch

Details

CVE ID CVE-2021-47243

Severity High

CVSS score 7.1 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2024-12-30

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47243?

CVE-2021-47243 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 4.19 onward and has been patched in 4.19.196, 5.4.128, 5.10.46 and others. CVE-2021-47243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47243?

CVE-2021-47243 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.
Is there a patch available for CVE-2021-47243?

Yes. CVE-2021-47243 has been patched. Fixed versions include 4.19.196, 5.4.128, 5.10.46 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47243 actively exploited?

No. CVE-2021-47243 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.