BaseIncomplete

CWE-1021Improper Restriction of Rendered UI Layers or Frames

Category: other

Description

The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain.

Common consequences· 1

  • Access Control — Gain Privileges or Assume Identity, Bypass Protection Mechanism, Read Application Data, Modify Application Data
    An attacker can trick a user into performing actions that are masked and hidden from the user's view. The impact varies widely, depending on the functionality of the underlying application. For example, in a social media application, clickjacking could be used to trick the user into changing privacy settings.

Potential mitigations· 4

  • [Implementation]
  • [Implementation]
  • [Implementation]This defense-in-depth technique can be used to prevent the improper usage of frames in web applications. It prioritizes the valid sources of data to be loaded into the application through the usage of declarative policies. Based on which implementation of Content Security Policy is in use, the developer should use the "frame-ancestors" directive or the "frame-src" directive to mitigate this weakness. Both directives allow for the placement of restrictions when it comes to allowing embedded content.
  • [Implementation]In addition to frames or iframes as previously mentioned, the web application is expected to place restrictions on whether it is allowed to be rendered within objects, embed, or applet elements.

Related CAPEC attack patterns· 7

CAPEC-103CAPEC-181CAPEC-222CAPEC-504CAPEC-506CAPEC-587CAPEC-654

References

  1. https://cwe.mitre.org/data/definitions/1021.html

Exploits (incoming)7

TypeTargetConfidenceTier
AttackPatternTask Impersonationcapec-504100%live
AttackPatternCross Frame Scripting (XFS)capec-587100%live
AttackPatterniFrame Overlaycapec-222100%live
AttackPatternFlash File Overlaycapec-181100%live
AttackPatternCredential Prompt Impersonationcapec-654100%live
AttackPatternTapjackingcapec-506100%live
AttackPatternClickjackingcapec-103100%live

(incoming)2

TypeTargetConfidenceTier
VulnerabilityCVE-2026-0007cve-2026-00070%live
VulnerabilityCVE-2026-22918cve-2026-229180%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CWE
Direct Request ('Forced Browsing')
CWE
Improper Access Control
CWE
Inclusion of Web Functionality from an Untrusted Source
CWE
Improper Authorization
CWE
Exposure of Data Element to Wrong Session
CWE
Permissive Cross-domain Security Policy with Untrusted Domains
Sourced from MITRE CWE 4.20. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.