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CVE Record

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.

MediumCVSS 6.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-36845 is a stored XSS issue in the YITH Maintenance Mode WordPress plugin through version 1.3.8. An authenticated, high-privilege user could save malicious content in plugin settings that later runs in another user’s browser. Business risk is mainly account compromise, content manipulation, and trust impact on affected WordPress sites.

Executive priority

Treat this as a medium-priority cleanup item unless the plugin is internet-facing on a high-value site or administrator access is weak. Prioritize removal or vendor-guided upgrade during the next WordPress maintenance cycle.

Technical view

The sources describe multiple authenticated stored XSS flaws across 46 YITH Maintenance Mode settings parameters. CVSS 3.1 is 6.9 with network attack vector, low complexity, high privileges required, user interaction required, changed scope, high confidentiality impact, low integrity impact, and no availability impact. The affected product is YITH Maintenance Mode for WordPress <= 1.3.8.

Likely exposure

Exposure is limited to WordPress sites with YITH Maintenance Mode installed at version 1.3.8 or earlier. Practical exploitation requires authenticated high-privilege access and a later page visit that triggers stored script execution.

Exploitation context

The source bundle does not show CISA KEV listing or other evidence of active exploitation. The issue is still relevant for stale WordPress installations, especially where administrator accounts are shared, weakly protected, or compromised.

Researcher notes

The bundle identifies affected versions and many vulnerable settings but does not name a fixed release. Avoid assuming patch status beyond vendor guidance. Validation should focus on plugin presence, version, privilege boundaries, and evidence of suspicious stored configuration.

Mitigation direction

  • Inventory WordPress sites for YITH Maintenance Mode and installed version.
  • If version is <= 1.3.8, follow vendor or WordPress plugin guidance immediately.
  • Disable or remove the plugin where it is not operationally required.
  • Restrict WordPress administrator access and enforce strong authentication.
  • Review plugin settings for unexpected scripts, HTML, URLs, or styling changes.

Validation and detection

  • Check whether YITH Maintenance Mode is installed and active.
  • Record plugin version and flag any installation at <= 1.3.8.
  • Review administrator accounts with access to plugin settings.
  • Inspect maintenance-mode configuration for suspicious saved content.
  • Check web and WordPress admin logs for unexpected configuration changes.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-79: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2021-36845 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.9 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.9CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N1.74.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.9Medium
CVSS 3.1 vector shape for CVE-2021-36845Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
YITHYITH Maintenance Mode (WordPress plugin)<= 1.3.8Listed
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-79 · source CWE mapping

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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