CVE Vulnerabilities

CVE-2021-33596

Improper Restriction of Rendered UI Layers or Frames

Published: Aug 05, 2021 | Modified: Aug 12, 2021
CVSS 3.x
4.1
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N
CVSS 2.x
3.5 LOW
AV:N/AC:M/Au:S/C:N/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu

Showing the legitimate URL in the address bar while loading the content from other domain. This makes the user believe that the content is served by a legit domain. Exploiting the vulnerability requires the user to click on a specially crafted, seemingly legitimate URL containing an embedded malicious redirect while using F-Secure Safe Browser for iOS.

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

Name Vendor Start Version End Version
Safe F-secure * 18.4.272901 (excluding)

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.

References