CVE-2023-41897

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.

Weakness

The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with.

Affected Software

Potential Mitigations

• The use of X-Frame-Options 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. There is a need for allowing frames from multiple domains.
• A developer can use a “frame-breaker” script in each page that should not be framed. This is very helpful for legacy browsers that do not support X-Frame-Options security feature previously mentioned.
• It is also important to note that this tactic has been circumvented or bypassed. Improper usage of frames can persist in the web application through nested frames. The “frame-breaking” script does not intuitively account for multiple nested frames that can be presented to the user.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/103.html
• https://cwe.mitre.org/data/definitions/181.html
• https://cwe.mitre.org/data/definitions/222.html
• https://cwe.mitre.org/data/definitions/504.html
• https://cwe.mitre.org/data/definitions/506.html
• https://cwe.mitre.org/data/definitions/587.html
• https://cwe.mitre.org/data/definitions/654.html

References

• https://github.com/home-assistant/core/security/advisories/GHSA-935v-rmg9-44mw
• https://github.com/home-assistant/core/security/advisories/GHSA-cr83-q7r2-7f5q
• https://www.home-assistant.io/blog/2023/10/19/security-audits-of-home-assistant/