CVE-2021-43400 : What You Need to Know

CVE-2021-43400 involves an issue in BlueZ 5.61, which can lead to a use-after-free scenario during D-Bus processing of a WriteValue call.

Understanding CVE-2021-43400

This CVE identifies a specific vulnerability in the BlueZ software version 5.61 that can result in a use-after-free situation under certain conditions.

What is CVE-2021-43400?

This CVE pertains to a flaw in the gatt-database.c component of BlueZ 5.61. The vulnerability arises when a client disconnects while D-Bus is processing a WriteValue call, potentially causing a use-after-free issue.

The Impact of CVE-2021-43400

The use-after-free scenario could lead to a system crash, denial of service, or potentially remote code execution, posing a significant risk to the security and stability of affected systems.

Technical Details of CVE-2021-43400

The technical aspects of this CVE reveal crucial insights into the vulnerability and its implications.

Vulnerability Description

The vulnerability lies in the gatt-database.c file of BlueZ 5.61, triggering a use-after-free condition during the handling of a disconnection event within the D-Bus processing of a WriteValue request.

Affected Systems and Versions

Vendor: Not applicable
Product: Not applicable
Affected Versions: All instances of BlueZ 5.61 are susceptible to this vulnerability.

Exploitation Mechanism

Exploiting this vulnerability requires triggering a disconnection event during the processing of a WriteValue call in the D-Bus interface of BlueZ 5.61, leading to the use-after-free condition.

Mitigation and Prevention

Understanding how to mitigate and prevent CVE-2021-43400 is crucial for maintaining system security.

Immediate Steps to Take

Update BlueZ to a patched version that addresses the vulnerability.
Monitor vendor communications and security advisories for relevant patches and updates.

Long-Term Security Practices

Regularly update system software and firmware to address security flaws.
Implement network segmentation and access controls to limit potential attack surfaces.

Patching and Updates

Ensure timely installation of patches and updates provided by the BlueZ project or relevant vendors to eliminate the vulnerability and enhance system security.