Linux Kernel up to 6.4.15/6.5.2 Bluetooth hci_conn use after free

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.4.15/6.5.2 and classified as critical. Affected by this vulnerability is the function hci_conn of the component Bluetooth. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2023-53374. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.4.15/6.5.2. This vulnerability affects the function hci_conn of the component Bluetooth. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fail SCO/ISO via hci_conn_failed if ACL gone early Not calling hci_(dis)connect_cfm before deleting conn referred to by a socket generally results to use-after-free. When cleaning up SCO connections when the parent ACL is deleted too early, use hci_conn_failed to do the connection cleanup properly. We also need to clean up ISO connections in a similar situation when connecting has started but LE Create CIS is not yet sent, so do it too here.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2023-53374 since 09/17/2025. The exploitation appears to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 12/12/2025).

The vulnerability scanner Nessus provides a plugin with the ID 265556 (Linux Distros Unpatched Vulnerability : CVE-2023-53374), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.4.16 or 6.5.3 eliminates this vulnerability. Applying the patch 397d58007532644b35fad746da48c41161f32a57/e94b898463a62b72a2a8b75dea8936bf4db78e00/3344d318337d9dca928fd448e966557ec5063f85 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (265556) and CERT Bund (WID-SEC-2025-2092). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6
• 6.4.7
• 6.4.8
• 6.4.9
• 6.4.10
• 6.4.11
• 6.4.12
• 6.4.13
• 6.4.14
• 6.4.15
• 6.5.0
• 6.5.1
• 6.5.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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