CVE-2021-3658 affects the BlueZ Bluetooth stack, specifically impacting the bluetoothd service. This vulnerability allows bluetoothd to incorrectly save the adapters' Discoverable status when a device is powered down. If a device is powered down while it is discoverable, it will remain discoverable upon power up. This behavior could lead to inadvertent exposure of the Bluetooth stack to physically nearby attackers, posing significant security risks.
The vulnerability has a CVSS score of 6.5, classifying it as medium severity. The attack vector is adjacent network, with low complexity and no privileges required. The potential confidentiality impact is high, indicating that sensitive information may be accessible to attackers in proximity.
Organizations using affected versions of BlueZ should prioritize addressing this vulnerability. The urgency for defenders is high, and organizations should consider implementing mitigations and patches as soon as possible to prevent unauthorized access to their Bluetooth-enabled devices.
As of now, there are no known public exploits for this vulnerability, though it is crucial to remain vigilant. The patch for this vulnerability is available, and organizations should ensure their systems are updated to the latest versions.
Vulnerability Details
The vulnerability is caused by the improper handling of the discoverable state of Bluetooth adapters. When a device is powered off while in a discoverable state, it retains that state upon being powered back on, which can be exploited by nearby attackers.
The CVSS score of 6.5 indicates a medium severity level, making it a risk worth addressing promptly. The affected products include BlueZ and Fedora, specifically versions prior to the vendor patch.
Technical Analysis
The root cause of CVE-2021-3658 is a flaw in the bluetoothd implementation within the BlueZ Bluetooth stack. When a device is powered down while in discoverable mode, the discoverable setting is incorrectly saved and restored, leading to potential unauthorized visibility.
The attack vector is adjacent network, meaning an attacker would need to be physically close to the device. The attack complexity is low, and no user interaction is required. The vulnerability does not require any privileges, allowing attackers to exploit it without authentication.
The confidentiality impact is high, indicating that sensitive data may be accessed, while integrity and availability impacts are noted as none. This means that the primary concern revolves around unauthorized access rather than service disruption.
Risk & Impact Analysis
The real-world risk associated with CVE-2021-3658 is significant, particularly for organizations utilizing Bluetooth technology in environments where devices may be physically accessible to attackers. The potential for data exposure can lead to privacy breaches and unauthorized access to sensitive information.
The blast radius for this vulnerability is concerning, as it impacts all devices using the affected versions of BlueZ. Organizations must recognize the urgency of addressing this vulnerability, especially given its CVSS score indicating medium severity and the high confidentiality impact.
Organizations should prioritize patching immediately to mitigate the risks associated with this vulnerability. Implementing updates and monitoring for any suspicious activity should be part of a comprehensive security strategy.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following versions of BlueZ are vulnerable to CVE-2021-3658: versions prior to 5.61. Additionally, Fedora 34 is affected. Organizations must ensure they are running updated versions to mitigate the risk.
Mitigation & Remediation
To mitigate the risk associated with CVE-2021-3658, organizations should apply the latest patches provided by BlueZ. Upgrading to version 5.61 or later is essential for protection against this vulnerability.
In cases where immediate patching is not feasible, organizations should consider implementing network controls to limit Bluetooth connectivity and monitor for any unauthorized access attempts. Regular security audits and assessments can help identify and remediate potential vulnerabilities.
For further guidance on securing Bluetooth implementations, organizations can refer to our application security assessment services to enhance their security posture.
Detection Guidance
Organizations should monitor logs for any anomalies related to Bluetooth connections. Indicators of potential exploitation include repeated attempts to connect to Bluetooth devices or unusual discoverable states.
Behavioral anomalies, such as unexpected device discoverability or unauthorized connections, should also be investigated. Network signatures related to Bluetooth traffic can provide additional context for identifying potential threats.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-3658 lies in the increasing reliance on Bluetooth technology across various devices, making vulnerabilities in this area particularly concerning. Organizations must adopt a proactive approach to security by implementing robust security measures to protect their devices from unauthorized access.
This vulnerability highlights the need for continuous monitoring and timely patching practices. Security teams should regularly review their Bluetooth configurations and ensure compliance with best practices for secure device operation.
For more insights on enhancing your security posture, consider exploring our penetration testing methodology and vulnerability management programs for ongoing risk assessment and remediation.
Understanding and addressing vulnerabilities like CVE-2021-3658 is critical in maintaining a secure environment, especially as the threat landscape continues to evolve.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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