What is CVE-2021-33033?

CVE-2021-33033 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416). CVE-2021-33033 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-33033?

CVE-2021-33033 has a CVSS score of 7.8 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:H/A:H.

Is there a patch available for CVE-2021-33033?

No patch is currently available for CVE-2021-33033. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-33033 actively exploited?

CVE-2021-33033 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2021-33033

High

The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.

Package Linux Kernel

Published 2021-05-14

Last modified 2024-11-21

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-416

CVE-2021-33033 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2021-33033 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Sites
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genopt

Exploit Third Party Advisory
Syzkaller
https://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701e

Exploit Mailing List Third Party Advisory
Kernel patch commit
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.14
Patch
Kernel patch commit
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7
Patch
Kernel patch commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1165affd484889d4986cf3b724318935a0b120d8
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2021-33033

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2021-05-14

Modified 2024-11-21

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-33033?

CVE-2021-33033 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2021-33033 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-33033?

CVE-2021-33033 has a CVSS score of 7.8 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:H/A:H.
Is there a patch available for CVE-2021-33033?

No patch is currently available for CVE-2021-33033. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-33033 actively exploited?

No — CVE-2021-33033 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →