CVE-2023-41893
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedHome 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 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOAuth parameter injection vulnerability in Home Assistant allows attackers to manipulate `redirect_uri` and `client_id` parameters during authentication. When a victim authenticates via a malicious link, the authorization code gets sent to an attacker-controlled URL instead of the legitimate instance, enabling token theft. The attack requires the victim to have their Home Assistant exposed to the internet and to click a crafted authentication link.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 2023.9.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Home Assistant versionLog into the Home Assistant web UI and look at the version displayed in the bottom left of the sidebar, or run `ha version` via the CLI if you have SSH access to the hostAffected if The displayed version is any version prior to 2023.9.0 (for example, 2023.8.4, 2023.7.0, etc.)
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Verify OAuth or cloud integration is configuredNavigate to Configuration > Integrations in the Home Assistant UI and look for Home Assistant Cloud (Nabu Casa) or any configured OAuth-based integrations such as Google Home, Amazon Alexa, or other cloud-linked servicesAffected if Any OAuth-dependent cloud service or integration is active and the version is vulnerable
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Check for external URL exposureGo to Configuration > General Settings and inspect the 'External URL' field. Also check your router or firewall for any port forwarding rules (typically ports 8123 or 443) pointing to your Home Assistant instanceAffected if An external URL is configured in Home Assistant or inbound NAT/port forwarding rules exist that make the instance reachable from the internet, combined with a vulnerable version
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Confirm remote access is enabledLook for the 'Remote Control' toggle in the Home Assistant Cloud settings or check for the 'homeassistant.remote' component being loaded in your configuration.yaml fileAffected if Remote control via Nabu Casa or manual remote access is enabled and the version is vulnerable
You are affected if your Home Assistant version is below 2023.9.0 AND you have OAuth-based integrations or cloud services configured AND your instance is accessible from the internet via an external URL or port forwarding.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2023.9.0
Upgrade Home Assistant to version 2023.9.0 or later. Avoid exposing Home Assistant to the internet if possible, and verify all OAuth redirect URLs before authenticating.
Home Assistant 2023.9.0 or later
- Upgrade Home Assistant to version 2023.9.0 or later by following the standard upgrade procedure for your installation method (e.g., Home Assistant OS, Container, Supervised, or Core)
- After upgrading, verify the version by checking the Home Assistant About page (Settings > System > About)
- Ensure the new version is running without issues before exposing the instance to the internet
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-41893 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-41893 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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