6.1
MEDIUM
CVE-2021-33829
CKEditor HTML Data Processor - Cross-Site Scripting Vulnerability
Description

A cross-site scripting (XSS) vulnerability in the HTML Data Processor in CKEditor 4 4.14.0 through 4.16.x before 4.16.1 allows remote attackers to inject executable JavaScript code through a crafted comment because --!> is mishandled.

INFO

Published Date :

June 9, 2021, 12:15 p.m.

Last Modified :

Nov. 21, 2024, 6:09 a.m.

Remotely Exploitable :

Yes !

Impact Score :

2.7

Exploitability Score :

2.8
Affected Products

The following products are affected by CVE-2021-33829 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fedoraproject fedora
1 Debian debian_linux
1 Drupal drupal
1 Ckeditor ckeditor
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-33829.

URL Resource
https://ckeditor.com/blog/ckeditor-4.16.1-with-accessibility-enhancements/#improvements-for-comments-in-html-parser Patch Release Notes Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/
https://www.drupal.org/sa-core-2021-003 Patch Third Party Advisory
https://ckeditor.com/blog/ckeditor-4.16.1-with-accessibility-enhancements/#improvements-for-comments-in-html-parser Patch Release Notes Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/
https://www.drupal.org/sa-core-2021-003 Patch Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-33829 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-33829 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://ckeditor.com/blog/ckeditor-4.16.1-with-accessibility-enhancements/#improvements-for-comments-in-html-parser
    Added Reference https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html
    Added Reference https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/
    Added Reference https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/
    Added Reference https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/
    Added Reference https://www.drupal.org/sa-core-2021-003
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/ [No types assigned]
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/ [No types assigned]
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/ [No types assigned]
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/
  • Modified Analysis by [email protected]

    Nov. 23, 2021

    Action Type Old Value New Value
    Changed Reference Type https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html No Types Assigned https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html Mailing List, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Nov. 17, 2021

    Action Type Old Value New Value
    Added Reference https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html [No Types Assigned]
  • Modified Analysis by [email protected]

    Nov. 10, 2021

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 10, 2021

    Action Type Old Value New Value
    Removed Reference https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html [No Types Assigned]
  • CVE Modified by [email protected]

    Nov. 09, 2021

    Action Type Old Value New Value
    Added Reference https://lists.debian.org/debian-lts-announce/2021/11/msg00007.html [No Types Assigned]
  • Modified Analysis by [email protected]

    Oct. 07, 2021

    Action Type Old Value New Value
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/ Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/ Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/ Mailing List, Third Party Advisory
    Changed Reference Type https://www.drupal.org/sa-core-2021-003 No Types Assigned https://www.drupal.org/sa-core-2021-003 Patch, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:* versions from (including) 8.9.0 up to (excluding) 8.9.16 *cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:* versions from (including) 9.0.0 up to (excluding) 9.0.14 *cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:* versions from (including) 9.1.0 up to (excluding) 9.1.9
  • CVE Modified by [email protected]

    Oct. 04, 2021

    Action Type Old Value New Value
    Added Reference https://www.drupal.org/sa-core-2021-003 [No Types Assigned]
  • CVE Modified by [email protected]

    Sep. 29, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/ [No Types Assigned]
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/ [No Types Assigned]
  • CVE Modified by [email protected]

    Sep. 25, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/ [No Types Assigned]
  • Initial Analysis by [email protected]

    Jun. 10, 2021

    Action Type Old Value New Value
    Added CVSS V2 Metadata Victim must voluntarily interact with attack mechanism
    Added CVSS V2 NIST (AV:N/AC:M/Au:N/C:N/I:P/A:N)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Changed Reference Type https://ckeditor.com/blog/ckeditor-4.16.1-with-accessibility-enhancements/#improvements-for-comments-in-html-parser No Types Assigned https://ckeditor.com/blog/ckeditor-4.16.1-with-accessibility-enhancements/#improvements-for-comments-in-html-parser Patch, Release Notes, Vendor Advisory
    Added CWE NIST CWE-79
    Added CPE Configuration OR *cpe:2.3:a:ckeditor:ckeditor:*:*:*:*:*:*:*:* versions from (including) 4.14.0 up to (excluding) 4.16.1
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-33829 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-33829 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.72 }} 0.18%

score

0.80397

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability