CVE-2025-53302: Constructor Auth Bypass Vulnerability

CVE-2025-53302 Overview

CVE-2025-53302 is a missing authorization vulnerability [CWE-862] in the Anton Shevchuk Constructor WordPress theme. The flaw affects all versions of Constructor up to and including 1.6.5. Unauthenticated attackers can access functionality that is not properly constrained by access control lists (ACLs) over the network. The vulnerability requires no privileges and no user interaction to exploit, limiting confidentiality impact only.

Critical Impact

Unauthenticated remote attackers can invoke theme functionality intended for privileged users, leading to limited information disclosure from affected WordPress sites.

Affected Products

• Anton Shevchuk Constructor WordPress theme versions through 1.6.5
• WordPress installations using the Constructor theme
• Sites without compensating access controls in front of WordPress

Discovery Timeline

• 2026-06-02 - CVE-2025-53302 published to the National Vulnerability Database
• 2026-06-02 - Last updated in NVD database

Technical Details for CVE-2025-53302

Vulnerability Analysis

The Constructor theme exposes one or more handlers that fail to verify the caller's authorization before executing. The pattern is typical of WordPress themes that register AJAX actions or admin endpoints without calling current_user_can() or validating a nonce with check_ajax_referer(). Attackers reach these handlers by issuing standard HTTP requests to wp-admin/admin-ajax.php or related endpoints. The vulnerability is exploitable across the network with low attack complexity and no authentication. Impact is limited to confidentiality, with no integrity or availability impact reported.

Root Cause

The root cause is missing authorization logic in privileged code paths within the Constructor theme. Code that should be reserved for administrators or editors executes for any caller, including anonymous visitors. This matches the CWE-862 weakness pattern, where the application performs a sensitive action without first verifying the caller's role or capability.

Attack Vector

An attacker sends crafted HTTP requests directly to the vulnerable theme endpoints. No session, cookie, or authentication token is required. Because Constructor is a public WordPress theme, attackers can fingerprint vulnerable installations by checking the theme path under /wp-content/themes/constructor/ and then invoke the unprotected handlers. Refer to the Patchstack WordPress Vulnerability Report for technical details specific to the exposed functionality.

Detection Methods for CVE-2025-53302

Indicators of Compromise

• Unauthenticated POST or GET requests to wp-admin/admin-ajax.php referencing Constructor-specific action names
• Requests targeting paths under /wp-content/themes/constructor/ from unfamiliar IP addresses
• Spikes in HTTP 200 responses to endpoints that previously required authentication
• Requests lacking valid WordPress nonce parameters yet receiving successful responses

Detection Strategies

• Inspect WordPress access logs for repeated calls to theme AJAX actions originating from unauthenticated sessions
• Correlate web server logs with WordPress audit trails to flag privileged actions tied to anonymous users
• Deploy web application firewall (WAF) rules that match known Constructor action handlers
• Use file integrity monitoring on the wp-content/themes/constructor/ directory to detect theme tampering

Monitoring Recommendations

• Forward WordPress and web server logs to a centralized log platform for correlation and retention
• Alert on bursts of admin-ajax.php traffic from single source IPs targeting the Constructor theme
• Track outbound data volumes from the WordPress host to detect bulk information disclosure
• Review user enumeration patterns that frequently precede broken access control exploitation

How to Mitigate CVE-2025-53302

Immediate Actions Required

• Inventory all WordPress sites and identify any using the Anton Shevchuk Constructor theme at version 1.6.5 or earlier
• Restrict access to wp-admin/ and admin-ajax.php from untrusted networks where feasible
• Deploy WAF rules to block unauthenticated requests to Constructor theme action handlers
• Review WordPress logs for prior exploitation attempts against the affected endpoints

Patch Information

No fixed version is identified in the published advisory at the time of writing. The vulnerability affects Constructor from unspecified earlier versions through 1.6.5. Monitor the Patchstack WordPress Vulnerability Report for vendor patch availability and apply updates immediately upon release.

Workarounds

• Replace the Constructor theme with a maintained alternative until a patched release is published
• Apply virtual patching through a WAF to block requests targeting the vulnerable theme endpoints
• Enforce IP allow-listing on the WordPress administrative interface to limit attacker reachability
• Disable the theme on staging and non-production sites that do not require it

# Example WAF rule concept to block anonymous Constructor AJAX calls
# Replace ACTION_NAME with the specific vulnerable action identifier
SecRule REQUEST_URI "@contains /wp-admin/admin-ajax.php" \
  "chain,deny,status:403,id:1005302,msg:'Block Constructor theme unauth access'"
  SecRule ARGS:action "@rx ^(ACTION_NAME)$" \
    "chain"
    SecRule &REQUEST_COOKIES:wordpress_logged_in_* "@eq 0"