CVE-2025-6238 Overview
CVE-2025-6238 is an open redirect vulnerability in the AI Engine plugin for WordPress, affecting version 2.8.4. The flaw resides in the plugin's OAuth implementation, where the redirect_uri parameter lacks validation during the authorization flow. An attacker can craft a malicious authorization request that redirects the user to an attacker-controlled URI, allowing interception of the authorization code and acquisition of an access token. The vendor, meowapps, addressed the issue in version 2.8.5 by disabling OAuth and removing the Meow_MWAI_Labs_OAuth class from the plugin. The vulnerability is classified under [CWE-601] (URL Redirection to Untrusted Site).
Critical Impact
Unauthenticated attackers can hijack OAuth authorization codes and obtain access tokens by tricking users into visiting crafted authorization URLs.
Affected Products
- meowapps AI Engine plugin for WordPress version 2.8.4
- WordPress sites running AI Engine with OAuth functionality enabled
- Installations using the Meow_MWAI_Labs_OAuth class prior to version 2.8.5
Discovery Timeline
- 2025-07-04 - CVE-2025-6238 published to NVD
- 2025-08-13 - Last updated in NVD database
Technical Details for CVE-2025-6238
Vulnerability Analysis
The AI Engine plugin implements an OAuth 2.0 authorization flow to enable third-party integrations. During this flow, the client application supplies a redirect_uri parameter that specifies where the authorization server should send the user after granting consent. In version 2.8.4, the plugin accepts this parameter without verifying it against a pre-registered allowlist of trusted URIs.
This missing validation breaks a core OAuth security requirement defined in RFC 6749. When a victim with an active WordPress session clicks an attacker-crafted authorization URL, the plugin processes the request and redirects the browser, along with the issued authorization code, to the attacker's chosen endpoint. The attacker then exchanges the code for an access token and assumes the victim's identity in API calls.
Root Cause
The root cause is improper input validation of the redirect_uri parameter in labs/oauth.php. The authorization handler does not compare the supplied URI against a registered list of permitted callback URLs before issuing the redirect and authorization code.
Attack Vector
Exploitation requires network access and user interaction. An attacker constructs a URL pointing to the legitimate WordPress site's OAuth authorization endpoint, but with the redirect_uri parameter pointing to an attacker-controlled domain. The victim must be logged in and authorize the request. After consent, the WordPress site redirects the browser, with the authorization code appended, to the attacker's server. The attacker submits the code to the token endpoint and receives a valid access token tied to the victim's account. See the Wordfence Vulnerability Report and the WordPress Plugin Source Code for technical details.
Detection Methods for CVE-2025-6238
Indicators of Compromise
- Web server access logs containing OAuth authorization requests with redirect_uri values pointing to external or unfamiliar domains.
- Unexpected outbound HTTP requests from user browsers to unknown hosts immediately following an OAuth consent action.
- API calls authenticated with OAuth tokens originating from IP addresses outside normal user geolocation patterns.
- Presence of the Meow_MWAI_Labs_OAuth class in labs/oauth.php on sites still running AI Engine 2.8.4 or earlier.
Detection Strategies
- Inspect HTTP request logs for OAuth endpoint hits and parse the redirect_uri query parameter, flagging values that do not match the site's own hostname.
- Compare the installed AI Engine plugin version against 2.8.5 across WordPress instances and flag any older versions.
- Monitor for anomalous OAuth token usage patterns, such as tokens used from new IPs or user agents shortly after issuance.
Monitoring Recommendations
- Enable verbose logging on the WordPress OAuth authorization and token endpoints to capture all redirect_uri values.
- Deploy a web application firewall rule that blocks OAuth authorization requests with external redirect_uri domains.
- Alert on file integrity changes to labs/oauth.php and labs/mcp.php within the AI Engine plugin directory.
How to Mitigate CVE-2025-6238
Immediate Actions Required
- Update the AI Engine plugin to version 2.8.5 or later on all WordPress sites.
- Audit existing OAuth tokens issued by the plugin and revoke any tokens of unknown origin.
- Review WordPress and web server logs for evidence of suspicious OAuth authorization requests prior to patching.
Patch Information
The vendor released AI Engine version 2.8.5, which disables OAuth functionality by no longer loading the Meow_MWAI_Labs_OAuth class. The fix is published in the WordPress Plugin Changeset for oauth.php and the WordPress Plugin Changeset for mcp.php.
Workarounds
- Deactivate the AI Engine plugin until version 2.8.5 or later can be installed.
- Block external access to the plugin's OAuth authorization endpoints at the web server or WAF layer.
- Restrict administrative WordPress users from authorizing OAuth requests originating from untrusted referrers.
# Update AI Engine via WP-CLI to the patched version
wp plugin update ai-engine --version=2.8.5
wp plugin list --name=ai-engine --fields=name,status,version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
