What CVEs are caused by CWE-1021?

186 recorded CVEs are attributed to CWE-1021, including CVE-2023-41897, CVE-2024-10004, CVE-2022-3167.

Is CWE-1021 actively exploited?

186 recorded CVEs are caused by CWE-1021; none are currently in CISA's KEV catalog of actively exploited flaws.

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Base weakness

Incomplete

CWE-1021: Improper Restriction of Rendered UI Layers or Frames

Also known as: Clickjacking, UI Redress Attack, Tapjacking

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

Last updated May 1, 2026

186

Recorded CVEs

With this primary weakness

0

KEVs

In the CISA KEV catalog

Not rated

Likelihood of exploit

Per MITRE

Base

Abstraction

MITRE classification

Overview

CWE-1021 (Improper Restriction of Rendered UI Layers or Frames) is a base-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.

Real-world CVEs

186 recorded CVEs are caused by CWE-1021 (Improper Restriction of Rendered UI Layers or Frames). The highest-severity and most recent are shown first. 30 new CWE-1021 CVEs have been recorded so far in 2026 (52 in 2025).

Showing 12 of 186 recorded CWE-1021 CVEs. Track new ones as they are published and get AI-written analysis and fixes.

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Common consequences

What can happen when CWE-1021 is exploited.

Gain Privileges or Assume Identity, Bypass Protection Mechanism, Read Application Data, Modify Application Data

Affects: Access Control

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.

How it happens

When it is introduced

Typically introduced during these phases of the software lifecycle.

Implementation

Applies to

Technologies

Web Based

How to prevent it

Practical mitigations for CWE-1021, grouped by where in the lifecycle they apply.

Implementation

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.

Implementation

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.

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.

How to detect it

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Effectiveness: High

Illustrative examples

Real CVEs that MITRE cites as examples of this weakness.

CVE-2017-7440 — E-mail preview feature in a desktop application allows clickjacking attacks via a crafted e-mail message
CVE-2017-5697 — Hardware/firmware product has insufficient clickjacking protection in its web user interface
CVE-2017-4015 — Clickjacking in data-loss prevention product via HTTP response header.
CVE-2016-2496 — Tapjacking in permission dialog for mobile OS allows access of private storage using a partially-overlapping window.
CVE-2015-1241 — Tapjacking in web browser related to page navigation and touch/gesture events.
CVE-2017-0492 — System UI in mobile OS allows a malicious application to create a UI overlay of the entire screen to gain privileges.

Terminology & mappings

Alternate terms

Clickjacking
UI Redress Attack
Tapjacking: "Tapjacking" is similar to clickjacking, except it is used for mobile applications in which the user "taps" the application instead of performing a mouse click.

Attack patterns

CAPEC attack patterns that exploit this weakness.

Frequently asked questions

Common questions about CWE-1021.

What is CWE-1021?: The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain.
What CVEs are caused by CWE-1021?: 186 recorded CVEs are attributed to CWE-1021, including CVE-2023-41897, CVE-2024-10004, CVE-2022-3167.
How do you prevent CWE-1021?: 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.
How is CWE-1021 detected?: Automated Static Analysis: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
What are the consequences of CWE-1021?: Exploiting CWE-1021 can lead to: Gain Privileges or Assume Identity, Bypass Protection Mechanism, Read Application Data, Modify Application Data.
Is CWE-1021 actively exploited?: 186 recorded CVEs are caused by CWE-1021; none are currently in CISA's KEV catalog of actively exploited flaws.

References

Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.

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Overview

Real-world CVEs

Common consequences

How it happens

When it is introduced

Applies to

How to prevent it

How to detect it

Automated Static Analysis

Illustrative examples

Related weaknesses

Parent

Terminology & mappings

Alternate terms

Attack patterns

Frequently asked questions

References

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