Cyber Resilience

CVE-2023-27482

Critical

Published: 08 March 2023

Published
08 March 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.9061 99.6th percentile
Risk Priority 74 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-27482 is a critical-severity Improper Authentication (CWE-287) vulnerability in Home-Assistant Home-Assistant. Its CVSS base score is 10.0 (Critical).

Operationally, ranked in the top 0.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

CVE-2023-27482 is an authentication bypass vulnerability (CWE-287) affecting the Home Assistant Supervisor component. It allows remote, unauthenticated access to the Supervisor API in all installation types using Supervisor 2023.01.1 or earlier; containerized or manually installed Core-only deployments are unaffected. The flaw carries a CVSS 3.1 score of 10.0.

An attacker with network access to an exposed Home Assistant instance can invoke Supervisor API endpoints without credentials, resulting in full compromise of confidentiality, integrity, and availability on the managed host.

Official advisories state the issue was fixed in Supervisor 2023.03.1, which was automatically deployed to all affected systems, and in Home Assistant Core 2023.3.0. Operators unable to upgrade are advised to avoid exposing the instance to the internet. Detailed technical write-ups are available from the elttam disclosure and the GitHub Security Advisory.

The associated EPSS score stands at 0.9061 with no subsequent rise indicated.

EU & UK References

Vulnerability details

homeassistant is an open source home automation tool. A remotely exploitable vulnerability bypassing authentication for accessing the Supervisor API through Home Assistant has been discovered. This impacts all Home Assistant installation types that use the Supervisor 2023.01.1 or older. Installation…

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types, like Home Assistant Container (for example Docker), or Home Assistant Core manually in a Python environment, are not affected. The issue has been mitigated and closed in Supervisor version 2023.03.1, which has been rolled out to all affected installations via the auto-update feature of the Supervisor. This rollout has been completed at the time of publication of this advisory. Home Assistant Core 2023.3.0 included mitigation for this vulnerability. Upgrading to at least that version is thus advised. In case one is not able to upgrade the Home Assistant Supervisor or the Home Assistant Core application at this time, it is advised to not expose your Home Assistant instance to the internet.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

home-assistant
home-assistant
≤ 2023.3.0
home-assistant
supervisor
≤ 2023.03.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-287

Detects unauthorized successful logons resulting from improper authentication implementations.

addresses: CWE-287

Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.

addresses: CWE-287

Security awareness training instructs users on secure authentication practices and avoiding credential compromise.

addresses: CWE-287

Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.

addresses: CWE-287

Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.

addresses: CWE-287

Session content review can reveal authentication bypasses or failures in session establishment.

addresses: CWE-287

Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.

addresses: CWE-287

Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.

References