CVE-2019-8921 Explained : Impact and Mitigation

A vulnerability was found in bluetoothd in BlueZ up to version 5.48 that could lead to the exposure of arbitrary heap data.

Understanding CVE-2019-8921

What is CVE-2019-8921?

The vulnerability involves the processing of a SVC_ATTR_REQ by the SDP implementation in BlueZ, allowing an attacker to deceive the server into exposing more bytes than the buffer can hold.

The Impact of CVE-2019-8921

This vulnerability could potentially lead to the exposure of sensitive heap data, posing a risk to the confidentiality and integrity of the affected system.

Technical Details of CVE-2019-8921

Vulnerability Description

The flaw lies in the function service_attr_req of sdpd-request.c, where the server fails to verify the consistency of CSTATE data in consecutive requests, assuming it remains unchanged.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions affected: up to BlueZ version 5.48

Exploitation Mechanism

The exploitation involves creating a malicious CSTATE to trick the server into providing more data than the buffer can accommodate, leading to the exposure of arbitrary heap data.

Mitigation and Prevention

Immediate Steps to Take

Apply the latest security updates provided by the vendor.
Monitor vendor advisories and security mailing lists for patches and mitigation guidance.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential attacks.
Regularly update and patch software to address known vulnerabilities.

Patching and Updates

Update BlueZ to a version beyond 5.48 to mitigate the vulnerability and enhance system security.