CVE-2025-9519 Overview
The Easy Timer plugin for WordPress contains a Remote Code Execution (RCE) vulnerability affecting all versions up to and including 4.2.1. The flaw resides in the plugin's shortcode handling, where attribute values are not sufficiently restricted before being processed. Authenticated users with Editor-level access or higher can leverage shortcode attributes to execute arbitrary code on the underlying server. The issue is classified under CWE-94: Improper Control of Generation of Code.
Critical Impact
Authenticated Editor-level attackers can achieve arbitrary code execution on the WordPress server, leading to full site compromise.
Affected Products
- WordPress Easy Timer plugin versions through 4.2.1
- WordPress installations where the Easy Timer plugin is active
- Sites with Editor-level or higher user accounts available to untrusted parties
Discovery Timeline
- 2025-09-04 - CVE-2025-9519 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-9519
Vulnerability Analysis
The Easy Timer plugin registers shortcodes that accept user-supplied attributes. The plugin processes these attributes without adequate validation or sanitization before they reach a code evaluation path. As a result, attacker-controlled input can influence executed code rather than being treated strictly as data.
Exploitation requires authentication at the Editor role or above, since shortcodes are typically embedded in posts or pages. The attack is conducted over the network and requires no user interaction once the malicious content is rendered. Successful exploitation compromises confidentiality, integrity, and availability of the affected WordPress instance.
Root Cause
The root cause is insufficient restriction of shortcode attributes in the plugin's shortcode handlers located in shortcodes.php. Attribute values are passed into logic that ultimately evaluates them as code, rather than being constrained to expected string formats, numeric ranges, or whitelisted values. The fix landed in WordPress Changeset #3355111, which tightens attribute handling.
Attack Vector
An authenticated attacker with Editor privileges creates or edits a post containing a crafted Easy Timer shortcode. The shortcode attribute carries a payload that the plugin interprets as code during rendering. When the page is viewed or previewed, the server executes the attacker's payload in the context of the PHP process running WordPress. Refer to the Wordfence Vulnerability Report and the Easy Timer shortcodes source for the affected code paths.
Detection Methods for CVE-2025-9519
Indicators of Compromise
- Unexpected PHP files written under wp-content/uploads/ or plugin directories following post edits
- WordPress posts or pages containing Easy Timer shortcodes with unusual attribute values referencing PHP functions or system commands
- Outbound network connections from the php-fpm or web server process to unknown hosts
- New or modified Editor and Administrator accounts created shortly after suspicious post activity
Detection Strategies
- Audit the wp_posts table for shortcodes referencing Easy Timer with attributes containing function names, backticks, or shell metacharacters
- Monitor WordPress audit logs for post creations or edits by Editor accounts that include the plugin's shortcodes
- Inspect web server access logs for POST requests to post.php and admin-ajax.php followed by anomalous GET requests rendering the modified content
Monitoring Recommendations
- Enable file integrity monitoring on the WordPress installation directory and plugin folder
- Alert on PHP process spawning shell utilities such as sh, bash, curl, or wget
- Track changes to user roles and capabilities in the WordPress database
How to Mitigate CVE-2025-9519
Immediate Actions Required
- Update the Easy Timer plugin to the patched release published after Changeset #3355111
- Audit Editor and Administrator accounts and remove any unnecessary high-privilege users
- Review recent post and page revisions for unexpected Easy Timer shortcodes
- Rotate WordPress administrator passwords and any database, API, or secret keys exposed to the web process
Patch Information
The vendor addressed the issue in WordPress Changeset #3355111, which restricts shortcode attribute handling in shortcodes.php. Site operators should upgrade to the first Easy Timer release that incorporates this changeset, published after version 4.2.1. The Wordfence advisory provides additional remediation guidance.
Workarounds
- Deactivate and remove the Easy Timer plugin until the patched version is deployed
- Restrict Editor and Author role assignments to fully trusted users only
- Apply a Web Application Firewall rule that blocks requests containing Easy Timer shortcode attributes with suspicious payloads
- Disable PHP execution in directories writable by the web server
# Disable the plugin via WP-CLI until patching is possible
wp plugin deactivate easy-timer
wp plugin delete easy-timer
# Identify posts containing the vulnerable shortcode
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%[easy-timer%';"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
