CVE-2025-53443: Axiomthemes Smash File Inclusion Flaw

CVE-2025-53443 Overview

CVE-2025-53443 is a PHP Local File Inclusion (LFI) vulnerability affecting the Axiomthemes Smash WordPress theme. The flaw stems from improper control of filenames passed to PHP include or require statements [CWE-98]. Attackers can manipulate file path parameters to load arbitrary local files through the theme's PHP execution context. The vulnerability affects all versions of Smash up to and including version 1.7. Successful exploitation can expose sensitive configuration files, credentials, and source code, and may lead to remote code execution when combined with file upload primitives or log poisoning techniques.

Critical Impact
Network-accessible Local File Inclusion in a WordPress theme allows unauthenticated attackers to read sensitive files and potentially execute arbitrary PHP code on the server.

Affected Products

Axiomthemes Smash WordPress theme versions through 1.7
WordPress sites using the vulnerable Smash theme
Hosting environments with the affected theme installed and active

Discovery Timeline

2025-12-18 - CVE-2025-53443 published to NVD
2026-01-20 - Last updated in NVD database

Technical Details for CVE-2025-53443

Vulnerability Analysis

The vulnerability is categorized under [CWE-98]: Improper Control of Filename for Include/Require Statement in PHP Program. The Smash theme accepts user-controlled input that is passed to a PHP include, include_once, require, or require_once statement without sufficient sanitization or path validation. This allows attackers to traverse the filesystem and load files outside the intended directory scope.

While the advisory classifies the issue as Local File Inclusion, the underlying CWE covers both LFI and Remote File Inclusion patterns. Exploitation requires no authentication and no user interaction, although the attack complexity is elevated, suggesting specific conditions or knowledge of theme parameters are needed to trigger the vulnerable code path.

Root Cause

The root cause is the absence of allowlist validation on file path parameters before they reach PHP file inclusion functions. PHP file inclusion executes the contents of the loaded file as code when the file contains PHP, making any include of attacker-influenced paths a code-execution risk. Without canonicalization checks, traversal sequences such as ../ allow access to arbitrary filesystem locations the web server can read.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker sends a crafted HTTP request to a Smash theme endpoint that processes a file path parameter. The PHP interpreter then includes the attacker-specified file. Common exploitation outcomes include reading wp-config.php to extract database credentials, leaking system files such as /etc/passwd, and chaining with uploaded media or log files containing PHP payloads to achieve remote code execution.

No public proof-of-concept exploit code has been published. Refer to the Patchstack WordPress Vulnerability advisory for additional technical context.

Detection Methods for CVE-2025-53443

Indicators of Compromise

HTTP requests to Smash theme PHP files containing path traversal sequences such as ../ or URL-encoded variants like %2e%2e%2f
Access log entries referencing sensitive filenames such as wp-config.php, /etc/passwd, or /proc/self/environ in query strings
Unexpected PHP errors in web server logs referencing include() or require() failures from theme directories
Outbound connections from the web server to attacker-controlled hosts following inclusion requests

Detection Strategies

Inspect web server and WordPress access logs for parameter values containing filesystem paths or traversal patterns directed at /wp-content/themes/smash/ endpoints
Deploy a Web Application Firewall (WAF) rule set that flags LFI signatures against WordPress theme paths
Monitor PHP error logs for failed to open stream warnings originating from Smash theme files

Monitoring Recommendations

Establish file integrity monitoring on wp-config.php and other configuration files to detect read access patterns
Alert on anomalous PHP process activity such as new outbound network connections or unexpected child processes spawned from the web server
Correlate WordPress plugin and theme inventory data with vulnerability feeds to identify hosts running Smash 1.7 or earlier

How to Mitigate CVE-2025-53443

Immediate Actions Required

Identify all WordPress installations running the Axiomthemes Smash theme and confirm version status
Deactivate the Smash theme on affected sites until a vendor-supplied patch is verified and installed
Rotate WordPress database credentials and any secrets stored in wp-config.php if exploitation is suspected
Apply WAF virtual patching rules that block path traversal sequences targeting theme endpoints

Patch Information

The vulnerability affects Smash versions through 1.7. At the time of publication, no fixed version is referenced in the NVD entry. Monitor the Patchstack advisory and the Axiomthemes vendor channels for an updated release.

Workarounds

Remove or disable the Smash theme and switch to a maintained theme until a patched version is available
Restrict web server file read permissions so the PHP process cannot access sensitive system files outside the webroot
Configure PHP open_basedir to confine file inclusion to the WordPress installation directory
Block direct HTTP access to theme PHP files that accept file path parameters via web server rules

bash

# Example php.ini hardening to limit file inclusion scope
open_basedir = "/var/www/html/:/tmp/"
allow_url_include = Off
allow_url_fopen = Off