Linux Kernel 4.15.0-118-generic Bluetooth CMTP double free

Summaryinfo

A vulnerability was found in Linux Kernel 4.15.0-118-generic. It has been declared as critical. This affects an unknown function of the component Bluetooth CMTP Module. Executing a manipulation can lead to double free. This vulnerability appears as CVE-2021-34981. The attack requires local access. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel 4.15.0-118-generic. This vulnerability affects some unknown processing of the component Bluetooth CMTP Module. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Linux Kernel Bluetooth CMTP Module Double Free Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the CMTP module. The issue results from the lack of validating the existence of an object prior to performing further free operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the kernel. Was ZDI-CAN-11977.

The advisory is available at zerodayinitiative.com. This vulnerability was named CVE-2021-34981 since 06/17/2021. The exploitation appears to be difficult. Local access is required to approach this attack. Additional levels of successful authentication are necessary for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/14/2025).

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.15.0-118-generic

License

• open-source

Website

• Vendor: https://www.kernel.org/

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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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