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

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.

Published: 2021-09-27 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36845 is rated Moderate Risk (53.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.71%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-36845

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-11 0.42% 0.71% +0.29%
2 2025-11-21 0.79% 0.42% -0.37%
3 2025-11-18 — 0.79% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36845

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
 1.7 4.7 [email protected]
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:L)
Some sensitive info could get out, but not a total data dump.
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.
 1.7 2.7 [email protected]
3.5 2.0 LOW
AV:N/AC:M/Au:S/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 6.8 2.9 [email protected]

Weakness enumeration for CVE-2021-36845

Affected software / configurations for CVE-2021-36845

Vendor Product Version Raw CPE
yithemes yith_maintenance_mode <= 1.3.8 cpe:2.3:a:yithemes:yith_maintenance_mode:*:*:*:*:*:wordpress:*:*

References for CVE-2021-36845

cvelogic Threat Intelligence