Summary
Home Assistant vulnerable to account takeover via auth_callback login
Part of the Cure53 security audit of Home Assistant.
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 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 the 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.
An attacker could increase the efficacy of this strategy by registering a nearly identical domain to homeassistant.local, which at first glance may appear legitimate and thereby obfuscate any malicious intentions.
Nonetheless, owing to the requirements for victim interaction and Home Assistant instance exposure to the Internet, this severity rating was consequently downgraded to Low.
Impact
CVE-2023-41893 has a CVSS score of 4.3 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2023.9.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2023-41893? CVE-2023-41893 is a medium-severity security vulnerability in homeassistant (pip), affecting versions >= 0, < 2023.9.0. It is fixed in 2023.9.0.
- How severe is CVE-2023-41893? CVE-2023-41893 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of homeassistant are affected by CVE-2023-41893? homeassistant (pip) versions >= 0, < 2023.9.0 is affected.
- Is there a fix for CVE-2023-41893? Yes. CVE-2023-41893 is fixed in 2023.9.0. Upgrade to this version or later.
- Is CVE-2023-41893 exploitable, and should I be worried? Whether CVE-2023-41893 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-41893 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-41893? Upgrade
homeassistantto 2023.9.0 or later.