core: Improper Restriction of Rendered UI Layers or Frames
CVE-2023-41897 is a critical-severity improper restriction of rendered UI layers or frames vulnerability in core from Home-assistant, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected core versions: < 2023.9.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.08% chance of exploitation within 30 days, higher than 66% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Home-assistant to 2023.9.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Home-assistant | core | < 2023.9.0 | Not stated |
| Home-assistant | Home-assistant | before 2023.9.0 | 2023.9.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA (github.com) |
| CVSS 3.1 | 9.6 | Critical | NVD |
Official description
Home assistant is an open source home automation. Home Assistant server does not set any HTTP security headers, including the X-Frame-Options header, which specifies whether the web page is allowed to be framed. The omission of this and correlating headers facilitates covert clickjacking attacks and alternative exploit opportunities, such as the vector described in this security advisory. This fault incurs major risk, considering the ability to trick users into installing an external and malicious add-on with minimal user interaction, which would enable Remote Code Execution (RCE) within the Home Assistant application. 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of Rendered UI Layers or Frames
The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain.
How developers prevent this class of flaw
- Use the frame-ancestors directive in the Content Security Policy, which is intended to define restrictions when it comes to allowing embedded content.
- The use of X-Frame-Options (now partially obsolete as of September 2026) allows developers of web content to restrict the usage of their application within the form of overlays, frames, or iFrames. The developer can indicate from which domains can frame the content. The concept of X-Frame-Options is well documented, but implementation of this protection mechanism is in development to cover gaps; often, there is a need for allowing frames from multiple domains.
- Use a frame-breaker script in each page that should not be framed. This is very helpful for legacy browsers that do not support the X-Frame-Options security feature previously mentioned (which is now partially obsolete).
More Improper Restriction of Rendered UI Layers or Frames vulnerabilities (CWE-1021)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in core
- 9.3 Critical severity
- 7.1 High severity
- 7.1 High severity
- 7.5 High severity
- 7.1 High severity
- 7.6 High severity
Recent Improper Restriction of Rendered UI Layers or Frames vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.3 High severity
- 7.3 High severity
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