What is CVE-2021-33034?

CVE-2021-33034 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-2021-33034 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-33034?

CVE-2021-33034 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-2021-33034?

No patch is currently available for CVE-2021-33034. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-33034 actively exploited?

CVE-2021-33034 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-2021-33034

High

In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. 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-2021-33034 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-2021-33034 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Debian Security
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html

Third Party Advisory
Debian Security
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html

Third Party Advisory
Lists
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/
Sites
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-hci_send_acl

Exploit Third Party Advisory
Syzkaller
https://syzkaller.appspot.com/bug?id=2e1943a94647f7732dd6fc60368642d6e8dc91b1

Exploit Mailing List Third Party Advisory
Kernel patch commit
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4
Patch
Kernel patch commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c4c8c9544099bb9043a10a5318130a943e32fc3
Patch

Details

CVE ID CVE-2021-33034

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-2021-33034?

CVE-2021-33034 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-2021-33034 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-33034?

CVE-2021-33034 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-2021-33034?

No patch is currently available for CVE-2021-33034. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-33034 actively exploited?

No — CVE-2021-33034 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 →