Cyber Resilience

CVE-2023-41893

Medium

Published: 20 October 2023

Published
20 October 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0026 49.9th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-41893 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Home-Assistant Home-Assistant. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 49.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Home assistant is an open source home automation. The audit team’s analyses confirmed that the `redirect_uri` and `client_id` are alterable when logging in. Consequently, the code parameter utilized to fetch the `access_token` post-authentication will be sent to the URL specified…

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in the aforementioned parameters. Since an arbitrary URL is permitted and `homeassistant.local` represents the preferred, default domain likely used and trusted by many users, an attacker could leverage this weakness to manipulate a user and retrieve account access. Notably, this attack strategy is plausible if the victim has exposed their Home Assistant to the Internet, since after acquiring the victim’s `access_token` the adversary would need to utilize it directly towards the instance to achieve any pertinent malicious actions. To achieve this compromise attempt, the attacker must send a link with a `redirect_uri` that they control to the victim’s own Home Assistant instance. In the eventuality the victim authenticates via said link, the attacker would obtain code sent to the specified URL in `redirect_uri`, which can then be leveraged to fetch an `access_token`. Pertinently, an attacker could increase the efficacy of this strategy by registering a near identical domain to `homeassistant.local`, which at first glance may appear legitimate and thereby obfuscate any malicious intentions. This issue has been addressed in version 2023.9.0 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

CWE(s)

Related Threats

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

Affected Assets

home-assistant
home-assistant
≤ 2023.9.0

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-200

Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.

addresses: CWE-200

Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.

addresses: CWE-200

Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.

addresses: CWE-200

By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.

addresses: CWE-200

Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.

addresses: CWE-200

Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.

addresses: CWE-200

Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.

addresses: CWE-200

Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.

References