CVE-2025-31589: Ethiopian Calendar Stored XSS Vulnerability

CVE-2025-31589 Overview

CVE-2025-31589 is a stored Cross-Site Scripting (XSS) vulnerability in the Kibru Demeke Ethiopian Calendar plugin for WordPress. The flaw affects all versions up to and including 1.1.1. It is classified under [CWE-79], Improper Neutralization of Input During Web Page Generation.

An authenticated attacker with low privileges can inject malicious scripts that persist in the application. Those scripts execute in the browsers of users who interact with the affected pages. Because the vulnerability crosses a security scope boundary, it can impact confidentiality, integrity, and availability of the affected site.

Critical Impact
Attackers can inject persistent JavaScript into the WordPress site, enabling session theft, administrative account takeover, and malicious redirects.

Affected Products

Kibru Demeke Ethiopian Calendar plugin for WordPress
All versions from initial release through 1.1.1
WordPress installations running the vulnerable plugin

Discovery Timeline

2025-03-31 - CVE-2025-31589 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31589

Vulnerability Analysis

The Ethiopian Calendar plugin fails to sanitize user-supplied input before rendering it within generated HTML output. An authenticated user submits crafted input containing JavaScript payloads. The plugin stores that input and later reflects it into pages served to other users.

Exploitation requires user interaction, meaning a victim must load a page that renders the injected payload. Once triggered, the script executes in the victim's browser context under the site's origin. The scope change indicates the impact extends beyond the vulnerable component to other parts of the WordPress environment, such as administrator sessions.

Root Cause

The root cause is missing output encoding and input sanitization in the plugin's data handling logic. WordPress provides sanitization APIs such as wp_kses_post(), esc_html(), and esc_attr(), which the plugin does not consistently apply. Untrusted input reaches the DOM as executable markup instead of inert text.

Attack Vector

The attack vector is network-based and requires a low-privileged authenticated account, such as Contributor or Author. The attacker submits a payload through a plugin field, form, or setting that stores user content. A subsequent visit by an administrator or another user triggers script execution. The Patchstack advisory documents the injection point and payload behavior. See the Patchstack Vulnerability Report for technical specifics.

Detection Methods for CVE-2025-31589

Indicators of Compromise

Unexpected <script> tags, onerror, onload, or javascript: URIs stored in WordPress post content, comments, or plugin-specific database tables
Outbound requests from administrator browsers to unfamiliar domains shortly after visiting calendar-related pages
New or modified administrator accounts and unexplained changes to plugin or theme files
Unusual entries in the wp_options or plugin data tables containing encoded JavaScript payloads

Detection Strategies

Query the WordPress database for stored payload patterns such as <script, onerror=, and document.cookie within plugin-managed fields
Deploy a Web Application Firewall (WAF) rule set that inspects POST requests to plugin endpoints for XSS signatures
Enable a Content Security Policy (CSP) in report-only mode to surface unexpected inline script execution

Monitoring Recommendations

Monitor WordPress audit logs for content edits performed by low-privileged accounts touching Ethiopian Calendar features
Alert on administrator session anomalies, including impossible travel and new IP address logins following calendar page visits
Track file integrity for wp-content/plugins/ethiopian-calendar/ and core WordPress files

How to Mitigate CVE-2025-31589

Immediate Actions Required

Deactivate and remove the Ethiopian Calendar plugin from all WordPress sites until a patched version is confirmed available
Audit user accounts and revoke unnecessary Contributor, Author, or Editor privileges that could be leveraged for exploitation
Rotate administrator passwords and invalidate active sessions if the plugin has been in use
Review recent plugin-managed content for injected scripts and remove any malicious entries

Patch Information

At the time of publication, no fixed version beyond 1.1.1 is referenced in the advisory. Site owners should consult the Patchstack Vulnerability Report for the current remediation status and vendor updates.

Workarounds

Uninstall the plugin and replace it with a maintained alternative that receives security updates
Restrict user registration and require manual approval to limit exposure to low-privileged attacker accounts
Deploy a WAF with rules that block common XSS payloads targeting WordPress plugin endpoints
Enforce a strict Content Security Policy that disallows inline scripts and unknown script sources

bash

# Example: disable the vulnerable plugin via WP-CLI
wp plugin deactivate ethiopian-calendar
wp plugin delete ethiopian-calendar

# Example: search the database for potential stored payloads
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%<script%' OR post_content LIKE '%onerror=%';"