Linux Kernel up to 6.1.41/6.4.6 Bluetooth hci_remove_adv_monitor use after free

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.41/6.4.6. This issue affects the function hci_remove_adv_monitor of the component Bluetooth. The manipulation leads to use after free. This vulnerability is traded as CVE-2023-54210. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.41/6.4.6. This issue affects the function hci_remove_adv_monitor of the component Bluetooth. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor() KASAN reports that there's a use-after-free in hci_remove_adv_monitor(). Trawling through the disassembly, you can see that the complaint is from the access in bt_dev_dbg() under the HCI_ADV_MONITOR_EXT_MSFT case. The problem case happens because msft_remove_monitor() can end up freeing the monitor structure. Specifically: hci_remove_adv_monitor() -> msft_remove_monitor() -> msft_remove_monitor_sync() -> msft_le_cancel_monitor_advertisement_cb() -> hci_free_adv_monitor() Let's fix the problem by just stashing the relevant data when it's still valid.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2023-54210 since 12/30/2025. The exploitation is known to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/26/2026).

Upgrading to version 6.1.42 or 6.4.7 eliminates this vulnerability. Applying the patch 0d4d6b083da9b033ddccef72d77f373c819ae3ea/bf00c2c8f6254f44ac041aa9a311ae9e0caf692b/de6dfcefd107667ce2dbedf4d9337f5ed557a4a1 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 vulnerability database at CERT Bund (WID-SEC-2025-2941). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• IBM Power Hardware Management Console
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Open Source Linux Kernel
• RESF Rocky Linux
• IBM DataPower Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.1.39
• 6.1.40
• 6.1.41
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion