CVE-2021-36845 MEDIUM

CVE-2021-36845: YITH Maintenance Mode (WordPress plugin) <= 1.3.8 - Multiple Authenticated Stored Cross-Site Scripting (XSS) vulnerabilities

Vendor Yith
Product YITH Maintenance Mode (WordPress plugin)
Weakness CWE-79 · XSS
Published September 27, 2021
Last update April 28, 2026

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction Required
Confidentiality High
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N

What the vulnerability does

01Description

Multiple Authenticated Stored Cross-Site Scripting (XSS) vulnerabilities in YITH Maintenance Mode (WordPress plugin) versions <= 1.3.8, there are 46 vulnerable parameters that were missed by the vendor while patching the 1.3.7 version to 1.3.8. Vulnerable parameters: 1 - "Newsletter" tab, &yith_maintenance_newsletter_submit_label parameter: payload should start with a single quote (') symbol to break the context, i.e.: NOTIFY ME' autofocus onfocus=alert(/Visse/);// v=' - this payload will be auto triggered while admin visits this page/tab. 2 - "General" tab issues, vulnerable parameters: &yith_maintenance_message, &yith_maintenance_custom_style, &yith_maintenance_mascotte, &yith_maintenance_title_font[size], &yith_maintenance_title_font[family], &yith_maintenance_title_font[color], &yith_maintenance_paragraph_font[size], &yith_maintenance_paragraph_font[family], &yith_maintenance_paragraph_font[color], &yith_maintenance_border_top. 3 - "Background" tab issues, vulnerable parameters: &yith_maintenance_background_image, &yith_maintenance_background_color. 4 - "Logo" tab issues, vulnerable parameters: &yith_maintenance_logo_image, &yith_maintenance_logo_tagline, &yith_maintenance_logo_tagline_font[size], &yith_maintenance_logo_tagline_font[family], &yith_maintenance_logo_tagline_font[color]. 5 - "Newsletter" tab issues, vulnerable parameters: &yith_maintenance_newsletter_email_font[size], &yith_maintenance_newsletter_email_font[family], &yith_maintenance_newsletter_email_font[color], &yith_maintenance_newsletter_submit_font[size], &yith_maintenance_newsletter_submit_font[family], &yith_maintenance_newsletter_submit_font[color], &yith_maintenance_newsletter_submit_background, &yith_maintenance_newsletter_submit_background_hover, &yith_maintenance_newsletter_title, &yith_maintenance_newsletter_action, &yith_maintenance_newsletter_email_label, &yith_maintenance_newsletter_email_name, &yith_maintenance_newsletter_submit_label, &yith_maintenance_newsletter_hidden_fields. 6 - "Socials" tab issues, vulnerable parameters: &yith_maintenance_socials_facebook, &yith_maintenance_socials_twitter, &yith_maintenance_socials_gplus, &yith_maintenance_socials_youtube, &yith_maintenance_socials_rss, &yith_maintenance_socials_skype, &yith_maintenance_socials_email, &yith_maintenance_socials_behance, &yith_maintenance_socials_dribble, &yith_maintenance_socials_flickr, &yith_maintenance_socials_instagram, &yith_maintenance_socials_pinterest, &yith_maintenance_socials_tumblr, &yith_maintenance_socials_linkedin.

Explanation of Vulnerability in Simple Terms

02Summary

The YITH Maintenance Mode plugin for WordPress contains a stored cross-site scripting (XSS) vulnerability in versions up to 1.3.8. An authenticated administrator with high privileges can inject malicious scripts through the plugin's settings. When other users view affected pages, the injected code executes in their browsers, potentially compromising their sessions or stealing sensitive data.

What an attacker can do

03Attacker Capabilities

Inject and store malicious JavaScript that executes when other users view the site.

Potential impact on your site

04Site Impact

Compromised admin accounts can inject persistent malware affecting all site visitors.

Conditions required to exploit

05Prerequisites

Attacker must be an authenticated administrator; victim must visit an affected page.

Key dates

06Disclosure timeline

September 27, 2021 CVE published
April 28, 2026 Record updated

Related vulnerabilities

08Related CVE