high
8.4
CWE
416
Advisory Published
CVE Published
Updated

CVE-2021-33034: Use After Free

First published: Mon Mar 22 2021(Updated: )

A use-after-free flaw was found in hci_send_acl in the bluetooth host controller interface (HCI) in Linux kernel, where a local attacker with an access rights could cause a denial of service problem on the system The issue results from the object hchan, freed in hci_disconn_loglink_complete_evt, yet still used in other places. The highest threat from this vulnerability is to data integrity, confidentiality and system availability.

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
redhat/kernel-rt<0:3.10.0-1160.36.2.rt56.1179.el7
0:3.10.0-1160.36.2.rt56.1179.el7
redhat/kernel<0:3.10.0-1160.36.2.el7
0:3.10.0-1160.36.2.el7
redhat/kernel<0:3.10.0-327.98.2.el7
0:3.10.0-327.98.2.el7
redhat/kernel<0:3.10.0-514.90.2.el7
0:3.10.0-514.90.2.el7
redhat/kernel<0:3.10.0-693.90.2.el7
0:3.10.0-693.90.2.el7
redhat/kernel<0:3.10.0-957.78.2.el7
0:3.10.0-957.78.2.el7
redhat/kernel<0:3.10.0-1062.52.2.el7
0:3.10.0-1062.52.2.el7
redhat/kernel-rt<0:4.18.0-305.7.1.rt7.79.el8_4
0:4.18.0-305.7.1.rt7.79.el8_4
redhat/kernel<0:4.18.0-305.7.1.el8_4
0:4.18.0-305.7.1.el8_4
redhat/kernel<0:4.18.0-147.51.1.el8_1
0:4.18.0-147.51.1.el8_1
redhat/kernel-rt<0:4.18.0-193.60.2.rt13.112.el8_2
0:4.18.0-193.60.2.rt13.112.el8_2
redhat/kernel<0:4.18.0-193.60.2.el8_2
0:4.18.0-193.60.2.el8_2
redhat/redhat-virtualization-host<0:4.3.17-20210713.0.el7_9
0:4.3.17-20210713.0.el7_9
redhat/redhat-virtualization-host<0:4.4.7-20210715.1.el8_4
0:4.4.7-20210715.1.el8_4
redhat/kernel<5.13
5.13
IBM Data Risk Manager<=2.0.6
Linux Kernel<5.12.4
Red Hat Fedora=34
Debian Linux=9.0
debian/linux
5.10.223-1
5.10.234-1
6.1.129-1
6.1.128-1
6.12.20-1
6.12.21-1

Remedy

Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.

Remedy

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4

Remedy

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c4c8c9544099bb9043a10a5318130a943e32fc3

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Reference Links

Parent vulnerabilities

(Appears in the following advisories)

Frequently Asked Questions

  • What is the severity of CVE-2021-33034?

    CVE-2021-33034 is classified as a high severity vulnerability that may lead to a denial of service.

  • How do I fix CVE-2021-33034?

    To fix CVE-2021-33034, update to the patched kernel versions specified in the advisory.

  • What types of systems are affected by CVE-2021-33034?

    CVE-2021-33034 affects various Linux kernel versions and distributions, particularly those using Red Hat and Debian.

  • Can CVE-2021-33034 be exploited remotely?

    CVE-2021-33034 requires local access to the system for exploitation, limiting its impact.

  • What are the potential impacts of CVE-2021-33034?

    The potential impact of CVE-2021-33034 includes system crashes and interruptions in service due to denial of service.

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