Critical Vulnerability in BlueZ Package: Double Free Issue Leading to Potential Denial of Service
Summary
ALPINE-CVE-2020-27153: In BlueZ before 5.55, a double free was found in the gatttool disconnect_cb() routine from shared/att.c. Affects bluez versions < 5.50-r5. Fixed in 5.50-r5. How to fix ↓
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Background
BlueZ is the official Linux Bluetooth protocol stack, providing support for core Bluetooth layers and protocols. It is widely used in various Linux distributions to enable Bluetooth functionality in devices. The package is essential for managing Bluetooth connections and services, making it a critical component for many applications relying on wireless communication. However, vulnerabilities in BlueZ can expose systems to significant risks, including unauthorized access and service disruptions.
Vulnerability Detail
In BlueZ versions prior to 5.55, a double free vulnerability was discovered in the gatttool disconnect_cb() routine located in shared/att.c. This flaw allows a remote attacker to exploit the disconnect MGMT event during service discovery, potentially leading to a denial of service or even arbitrary code execution. The vulnerability arises from improper memory management, where the same memory is freed multiple times, leading to unpredictable behavior and security risks.
How To Fix
Minimum fixed version
5.50-r5
This is the first release that contains the fix.
sudo apk add --upgrade bluezTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users can disable Bluetooth services until the package is updated. This can be done by stopping the Bluetooth service with the command: 'service bluetooth stop'. However, this is not a permanent solution and updating the package is strongly recommended.
Conclusion
The BlueZ package has a critical vulnerability that can lead to severe security risks, including denial of service and code execution. It is essential for users to update their BlueZ installations to the latest patched versions to protect their systems. Additionally, utilizing tools like Vulert can help monitor and alert for such vulnerabilities in real-time.
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FAQ
The CVSS score of this vulnerability is 8.6, indicating a high severity level.
BlueZ versions prior to 5.55 are affected by this vulnerability.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without any signup.
The potential consequences include denial of service and arbitrary code execution, which can compromise system integrity and security.
Yes, the permanent fix is to update the BlueZ package to the latest patched version as specified in the 'how_to_fix' section.
References
Related vulnerabilities
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