CVE-2025-15490 Overview
CVE-2025-15490 is an authorization bypass vulnerability in the Passster WordPress plugin versions prior to 4.2.26. The plugin provides password protection for WordPress content, but its global protection checks contain a logic flaw. Unauthenticated attackers can bypass the protection mechanism using crafted URLs, gaining access to content that should require a password. The issue is categorized under [CWE-863] Incorrect Authorization.
Critical Impact
Unauthenticated remote attackers can access password-protected WordPress content by manipulating URL parameters, defeating the plugin's core content-gating function.
Affected Products
- Passster WordPress plugin versions before 4.2.26
- WordPress sites relying on Passster for global content protection
- Any deployment using Passster's URL-based protection checks
Discovery Timeline
- 2026-09-02 - CVE-2025-15490 published to NVD
- 2026-09-02 - Last updated in NVD database
Technical Details for CVE-2025-15490
Vulnerability Analysis
The Passster plugin enforces content access controls through global protection checks executed on incoming requests. These checks determine whether a visitor has satisfied the password requirement before rendering protected content. The plugin fails to validate all URL variants that reach the same protected resource, creating a gap between the enforcement layer and the content delivery layer.
An unauthenticated attacker exploits this gap by crafting a URL that the protection routine does not recognize as requiring enforcement. The request bypasses the password prompt entirely and returns the underlying content. Because the flaw sits in the authorization decision logic rather than credential handling, no brute-force or credential guessing is required.
The confidentiality impact is limited to content the site owner intended to gate. Integrity and availability are not affected, consistent with the vulnerability's scope as an unauthorized-read condition.
Root Cause
The root cause is incorrect authorization logic ([CWE-863]) in the global protection checks. The plugin evaluates request context inconsistently, so certain crafted URLs reach protected resources without passing the access check. Refer to the WPScan Vulnerability Report for technical details.
Attack Vector
Exploitation occurs over the network with no authentication or user interaction. An attacker sends an HTTP request with a crafted URL to the target WordPress site. The plugin's protection logic fails to match the request against its protected-resource ruleset and returns the content. The attack requires no special tooling beyond an HTTP client.
No verified exploit code is publicly available. See the WPScan Vulnerability Report for further context.
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Stop Identity AttacksDetection Methods for CVE-2025-15490
Indicators of Compromise
- Web server access logs showing successful 200 OK responses to protected URLs from clients that never submitted the Passster password form.
- Requests to protected pages containing unusual query strings, path variations, or trailing parameters preceding successful content retrieval.
- Absence of the Passster session cookie on requests that nonetheless return protected content.
Detection Strategies
- Compare access log entries for protected URLs against Passster authentication events to identify content served without a preceding password submission.
- Deploy web application firewall rules that alert on requests to known protected paths lacking a valid Passster session cookie.
- Audit the installed Passster plugin version across WordPress sites and flag any instance below 4.2.26.
Monitoring Recommendations
- Monitor WordPress plugin inventories for outdated Passster installations and correlate with public exposure of protected content.
- Track anomalous spikes in requests to URLs that Passster is configured to protect.
- Enable HTTP request logging with full URL and referrer fields to support post-incident analysis of bypass attempts.
How to Mitigate CVE-2025-15490
Immediate Actions Required
- Update the Passster WordPress plugin to version 4.2.26 or later on all affected sites.
- Inventory WordPress deployments to identify every instance of Passster and confirm remediation status.
- Review web server access logs for evidence of unauthorized access to protected content prior to patching.
Patch Information
The vendor addressed CVE-2025-15490 in Passster version 4.2.26. Site administrators should upgrade through the WordPress plugin management interface or by deploying the updated plugin package. Refer to the WPScan Vulnerability Report for advisory details.
Workarounds
- If immediate patching is not possible, disable the Passster plugin and gate sensitive content through WordPress native password protection or authenticated user roles.
- Restrict access to protected URLs at the web server or reverse proxy layer using IP allowlists until the plugin is updated.
- Remove or unpublish highly sensitive content from the site until the fixed plugin version is deployed.
# Update Passster via WP-CLI
wp plugin update passster --version=4.2.26
wp plugin list --name=passster --fields=name,status,version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
