Widget feature vulnerability allowing to execute JavaScript code using undo functionality

CVE-2021-32808 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Affected packages

The vulnerability has been discovered in Widget plugin if used alongside Undo feature.

Impact

A potential vulnerability has been discovered in CKEditor 4 Widget package. The vulnerability allowed to abuse undo functionality using malformed widget HTML, which could result in executing JavaScript code. It affects all users using the CKEditor 4 plugins listed above at version >= 4.13.0.

Patches

The problem has been recognized and patched. The fix will be available in version 4.16.2.

For more information

Email us at [email protected] if you have any questions or comments about this advisory.

Acknowledgements

The CKEditor 4 team would like to thank Anton Subbotin (skavans) for recognizing and reporting this vulnerability.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2021-08-23 19:40:48 UTC
Updated
2023-02-01 05:05:53 UTC
GitHub reviewed
2021-08-23 16:49:07 UTC
NVD published
2021-08-12

EPSS Score

Score Percentile
1.37% 79.93%

CVSS Scores

Base score Version Severity Vector
7.6 3.1 —
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

Type Value
GHSA GHSA-6226-h7ff-ch6c ↗
CVE CVE-2021-32808 ↗

CWEs

CWE id Name
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm ckeditor4 >= 4.13.0, < 4.16.2 4.16.2 —

References

cvelogic Threat Intelligence