CVE-2019-11893 : Security Advisory and Response

A potential vulnerability exists in the app permission update API of the Bosch Smart Home Controller (SHC) version earlier than 9.8.905, allowing a restricted app to gain default app permissions.

Understanding CVE-2019-11893

This CVE involves an incorrect privilege assignment in the app permission update API of the Bosch Smart Home Controller.

What is CVE-2019-11893?

The vulnerability in the Bosch Smart Home Controller could enable a restricted app to acquire default app permissions, potentially leading to unauthorized access.

The Impact of CVE-2019-11893

The vulnerability poses a medium severity risk with a CVSS base score of 5.5. If exploited, it could result in a restricted app gaining default app permissions.

Technical Details of CVE-2019-11893

This section provides detailed technical information about the CVE.

Vulnerability Description

The vulnerability allows a restricted app to obtain default app permissions in the Bosch Smart Home Controller.

Affected Systems and Versions

Product: Smart Home Controller
Vendor: Bosch
Versions Affected: < 9.8.905 (unspecified/custom)

Exploitation Mechanism

To exploit this vulnerability, the attacker must have already paired an app with restricted permissions, which requires user interaction.

Mitigation and Prevention

Protecting systems from CVE-2019-11893 is crucial to prevent unauthorized access and maintain security.

Immediate Steps to Take

Update the Bosch Smart Home Controller to version 9.8.905 or higher to mitigate the vulnerability.
Regularly monitor app permissions and revoke unnecessary access.

Long-Term Security Practices

Implement strong authentication mechanisms for app pairing.
Conduct regular security assessments and audits to identify and address vulnerabilities.

Patching and Updates

Stay informed about security updates from Bosch and apply patches promptly to address known vulnerabilities.