CVE-2018-21019 in Home Assistant
Summary
by MITRE
Home Assistant before 0.67.0 was vulnerable to an information disclosure that allowed an unauthenticated attacker to read the application's error log via components/api.py.
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Analysis
by VulDB Data Team • 12/27/2023
The vulnerability identified as CVE-2018-21019 affects Home Assistant versions prior to 0.67.0, representing a critical information disclosure flaw that exposes sensitive system data to unauthenticated attackers. This vulnerability resides within the application's api.py component, specifically in how the system handles error log retrieval requests. The flaw allows malicious actors to access detailed error logs without requiring any authentication credentials, potentially exposing system internals, configuration details, and other sensitive operational information.
The technical implementation of this vulnerability stems from insufficient access controls within the Home Assistant API framework. When error logs are generated during application operation, the system fails to properly validate incoming requests to the api.py module, particularly those targeting error log retrieval endpoints. This design oversight creates an attack vector where any external party can submit a request to access these logs, bypassing all authentication mechanisms. The error logs typically contain detailed stack traces, system paths, user data, and configuration parameters that could be leveraged by attackers for further exploitation. This weakness aligns with CWE-200, which defines information exposure vulnerabilities where sensitive data is accessible to unauthorized parties.
The operational impact of this vulnerability extends beyond simple information disclosure, as the error logs often contain rich contextual data that could enable more sophisticated attacks. Attackers could potentially extract database connection strings, API keys, system paths, and other sensitive configuration parameters from the exposed logs. This information could then be used to launch targeted attacks against the Home Assistant system or to identify additional vulnerabilities within the broader network infrastructure. The exposure of system internals also provides attackers with insights into the application's architecture and implementation details, facilitating advanced persistent threat campaigns. According to ATT&CK framework, this vulnerability maps to T1083 (File and Directory Discovery) and T1566 (Phishing with Social Engineering) as attackers can use the disclosed information to craft more convincing social engineering attacks.
Mitigation strategies for CVE-2018-21019 primarily involve upgrading to Home Assistant version 0.67.0 or later, where the vulnerability has been addressed through proper authentication enforcement. System administrators should also implement network-level protections such as firewalls and access control lists to restrict access to the Home Assistant API endpoints. Additionally, organizations should conduct regular security assessments of their home automation systems, implement proper log monitoring, and establish network segmentation to limit potential attack surfaces. The fix implemented in version 0.67.0 likely includes enhanced authentication checks and proper input validation for error log retrieval requests, ensuring that only authorized users can access sensitive system information. Regular security updates and patch management processes should be maintained to prevent similar vulnerabilities from being introduced in future releases.