Local File Inclusion in the “Post Slides” WordPress Plugin (<= 1.0.1): What Site Owners Must Do Right Now

तारीख: 10 फरवरी 2026   |   CVE: CVE-2025-15491   |   गंभीरता: CVSS 7.5 (High) — Local File Inclusion (LFI)

As a Hong Kong-based WordPress security practitioner, I’ll explain what this vulnerability means, how attackers may exploit it in real sites, and the precise actions you must take immediately. This guidance is written for site owners, administrators, developers, and agencies that operate WordPress at scale. No marketing — straight, practical advice.

कार्यकारी सारांश (संक्षिप्त)

• A Local File Inclusion (LFI) vulnerability affects the Post Slides plugin (versions ≤ 1.0.1). An attacker with Contributor-level privileges (or equivalent, depending on configuration) can cause the plugin to include arbitrary local files and display their contents.
• CVSS 7.5 reflects high impact from disclosure of sensitive information (for example, wp-config.php contents). In some environments, chaining with other weaknesses can lead to full compromise.
• No vendor-published patched version is available at time of disclosure. Manual mitigations, removal, or virtual patching are required until a secure release is published.
• Treat this as urgent: disable or remove the plugin, restrict access, and perform a full site integrity check immediately if the plugin is present.

What is Local File Inclusion (LFI) and why it’s dangerous

Local File Inclusion occurs when server-side code accepts a file path from user input and uses it in include/require or file-reading functions without proper validation. Attackers can force inclusion of arbitrary filesystem files instead of the intended resource. Common targets include:

• wp-config.php (डेटाबेस क्रेडेंशियल और साल्ट)
• configuration or backup files in webroot
• plugin/theme files containing secrets
• log files that may contain credentials or session tokens

An LFI typically allows reading sensitive data. In environments where an attacker can write to logs or upload files, LFI may be escalated to remote code execution (RCE).

Why this report matters: the vulnerability can be triggered by low-privilege accounts (Contributor). Many sites accept guest submissions or have multi-user editorial workflows, increasing exposure. The plugin is also installed on many sites; attackers can automate detection and exploitation at scale.

How attackers could (and would) abuse this plugin vulnerability

I won’t provide exploit code, but these realistic attack patterns describe what to look for and how to respond.

1. Credential disclosure: Forcing inclusion of wp-config.php reveals DB credentials and salts. With database credentials an attacker can pivot to extract or modify data (or reuse credentials elsewhere).
2. Information harvesting: Reading files reveals installed components, absolute paths, PHP config, and other useful reconnaissance.
3. Log poisoning + LFI → RCE: If an attacker can write PHP to an accessible file (via upload or logging), including that file via LFI can produce code execution.
4. Persistence and lateral movement: After gaining credentials or code execution, an attacker may create admin users, drop backdoors, or schedule malicious cron jobs.

Given these outcomes, an LFI that accepts file-like input is high-risk and requires immediate mitigation.

कौन जोखिम में है

• Any WordPress site with Post Slides installed and version ≤ 1.0.1.
• Sites that allow Contributor or similar roles, including blogs with guest submissions.
• Sites with weak file permissions, insecure uploads, or hosting misconfiguration exposing internal files.
• WordPress multisite networks where a single plugin can affect multiple sites.

If uncertain whether the plugin is installed, check the Admin Plugins screen or list wp-content/plugins on the server if you have shell access.

Immediate (first 60 minutes) steps for site owners & administrators

1. उपस्थिति और संस्करण की पहचान करें
   • WordPress Admin → Plugins → locate “Post Slides”. If version ≤ 1.0.1, proceed urgently.
2. प्लगइन को निष्क्रिय करें
   • Deactivate immediately to stop the vulnerable code from executing.
   • If you cannot deactivate without disrupting service, place the site in maintenance/staging mode and restrict access.
3. Remove plugin files if feasible
   • After deactivation, delete the plugin directory from wp-content/plugins via SFTP if possible.
4. योगदानकर्ता पहुंच को प्रतिबंधित करें
   • Temporarily revoke Contributor privileges or restrict new user creation until the issue is resolved.
   • Audit existing contributor accounts for suspicious activity.
5. Harden file permissions (quick check)
   • Ensure common permissions: files 644, directories 755, and tighten wp-config.php to 640 or 600 where supported.
6. समझौते के संकेतों के लिए स्कैन करें
   • Look for suspicious admin users, recent file modifications, unknown PHP files in /wp-content/uploads, odd scheduled tasks, and unexpected DB changes.
   • Run reputable malware scanners or host-provided security tools where available.
7. क्रेडेंशियल्स को घुमाएं
   • If wp-config.php may have been read, rotate your database password and update wp-config.php. Rotate API keys and any exposed secrets.
8. बैकअप
   • Take a full file and database backup before further clean-up to preserve evidence and enable recovery.

Short-term mitigations (until an official plugin patch is available)

• Keep the plugin disabled/removed until a patched release is available.
• WAF के माध्यम से आभासी पैचिंग: Configure Web Application Firewall rules to block LFI patterns:
  • Block directory traversal sequences (../) in parameters.
  • Block PHP stream wrappers (php://, data:, zip://).
  • Block requests referencing core files (wp-config.php).
  • Limit access to the plugin’s endpoints if you can identify them.
• योगदानकर्ता क्षमताओं को सीमित करें: Remove upload or dangerous capabilities from non-trusted roles.
• Harden uploads: Prevent execution of PHP in upload directories via .htaccess or server configuration.
• ऑडिट लॉग: Retain web access logs (30+ days) to investigate potential exploitation.

Detection: How to know if you were targeted or exploited

Indicators of Compromise (IOCs) to look for:

Server-side indicators

• Access logs showing requests to wp-config.php, .env, or backup files that returned 200.
• Requests with URL-encoded directory traversal or PHP stream wrappers in parameters.
• Unusual query strings to plugin endpoints.

Application-side indicators

• New administrator accounts created without authorization.
• Posts/pages with injected code or posts authored by unknown contributors.
• PHP files appearing in /wp-content/uploads or subdirectories.
• Unfamiliar scheduled tasks (wp-cron entries).

व्यवहारिक संकेतक

• Unexpected password reset emails or other account-related activity.
• Outbound connections from the server that are unusual or unauthorized.
• CPU or IO spikes consistent with cryptomining or scanning activity.

यदि आप शोषण के सबूत पाते हैं:

• Take the site offline or restrict it to trusted IPs to prevent further damage.
• Collect logs and snapshots and engage incident response for forensic analysis.
• Reset WordPress account passwords, database credentials, and service keys that might be compromised.

Recovery and remediation checklist (post-incident)

1. रोकथाम: Isolate the server or site if active compromise is suspected.
2. जांच: Preserve full backups and logs; record modified files and DB snapshots.
3. उन्मूलन: Remove malicious files and backdoors; replace compromised core/plugin/theme files with clean copies from official sources.
4. क्रेडेंशियल रोटेशन: Reset admin passwords, DB credentials, and API keys.
5. पैच करें: Apply plugin/theme/core updates from the official author when a fix is released.
6. निगरानी: Enable file integrity monitoring and continuous scanning.
7. सीखे गए पाठ: Document the attack timeline, vector, and remediation; update policies and controls.

If you lack in-house incident response capability, engage a reputable managed security or forensics provider for containment and remediation.

How to harden WordPress to reduce LFI and similar risks

• Disallow plugin and theme file editing: add define(‘DISALLOW_FILE_EDIT’, true); to wp-config.php.
• Prevent execution of PHP in /wp-content/uploads via .htaccess or server configuration.
• Enforce least privilege for WordPress roles; remove create_users and install_plugins from non-admins.
• Use strong unique passwords and enable 2FA for admin and editor accounts.
• Restrict wp-admin access by IP where practical.
• प्लगइन्स और थीम को अपडेट रखें; अप्रयुक्त घटकों को हटा दें।.
• Implement logging and monitoring for web server, application events, and WAF alerts.
• Set appropriate file permissions to avoid world-writable content.
• Use environment-specific secrets; avoid storing credentials in webroot or version control.
• नियमित बैकअप बनाए रखें और पुनर्स्थापना प्रक्रियाओं का परीक्षण करें।.

WAF-focused guidance (for platform operators and technical teams)

A properly tuned Web Application Firewall is an effective short-term mitigation for LFI disclosures when a vendor patch is not yet available.

• Detect and block directory traversal patterns such as “../”.
• Block stream wrappers and suspicious wrapper strings: php://, expect://, data:text/php, zip:// etc.
• Block attempts to include critical files (wp-config.php, .env) in parameters.
• Rate-limit and block suspicious accounts that test multiple inclusion vectors.
• Tailor rules to the plugin endpoint and parameter names where identifiable; test in log-only mode before enabling blocking.

How to validate a site is clean after mitigation

• Re-scan with multiple reputable malware scanners.
• Check for recently modified PHP files, particularly in uploads, themes, and plugin directories.
• Review the database for suspicious users, posts, or wp_options entries.
• Verify no unexpected scheduled WP cron jobs exist.
• Confirm there are no unknown outgoing connections or server-level cron tasks.
• Test core workflows and public pages to ensure integrity.
• Consider a third-party penetration test or professional security review for higher assurance.

If unsure, engage professional forensic help before returning the site to production.

Communication and disclosure considerations if your site was affected

• Prepare a concise incident summary for stakeholders covering scope, impact, actions taken, and next steps.
• If user data was exposed, comply with applicable privacy regulations and notify affected users as required.
• Be transparent about remediation and advise users to rotate passwords where relevant.
• Preserve logs and evidence in case legal or regulatory reporting is required.

Practical example — safe, high-level analysis (what to look for in logs)

Conceptual examples of suspicious requests:

GET /?post_slides_param=../../wp-config.php HTTP/1.1
POST /wp-admin/admin-ajax.php?action=post_slides_fetch&file=php://filter/convert.base64-encode/resource=wp-config.php

Such requests indicate attempts to read wp-config.php via file path parameters or PHP stream wrappers. Treat them as high priority.

Why you should treat Contributor-privilege bugs seriously

Lower-privileged roles like Contributor are often used in editorial workflows and are not expected to perform filesystem operations. When a bug expands their capabilities, risk increases:

• Guest contributors or compromised contributor accounts provide inexpensive attack vectors.
• These roles are frequently overlooked in audits, creating persistent exposure.
• Sites accepting user-submitted content should enforce sanitization, upload limits, and editorial moderation.

If your site uses Contributor roles, review permissions and consider temporary restrictions until the vulnerability is resolved.

Preventive measures for development teams

• Never use user input directly in include/require calls.
• Use strict allow-lists for permitted filenames and paths; avoid deny-only approaches.
• Normalize and validate paths; use realpath and ensure results remain within an expected base directory.
• Sanitize input to block stream wrappers (php://, data:, zip://).
• Harden endpoints that accept file names or file-like input.
• Include secure coding reviews and automated SAST checks to detect unsafe file operations.

अक्सर पूछे जाने वाले प्रश्न

Q: My site depends on Post Slides functionality. What should I do?

A: Evaluate whether you can replace functionality temporarily (static slides, a trusted page builder, or manual HTML). If production use is unavoidable, run the plugin only in a sandbox or staging environment, apply strict WAF rules and least-privilege access, and monitor closely.

Q: If I remove the plugin, will data be lost?

A: Most plugins store data in WP tables or custom post types. Deactivating typically preserves data in the DB, but always take a backup before removal and test in staging.

Q: Are automatic updates safe?

A: Automatic updates are useful for critical fixes, but test patches in staging before applying to production on complex sites. Have a rapid rollback plan.

Final operational checklist

1. Immediately identify if Post Slides (≤ 1.0.1) is installed. If yes: deactivate and remove plugin files.
2. Scan for and investigate signs of compromise (access logs, unexpected admin creation, PHP files in uploads).
3. Rotate database and API credentials if exposure is suspected.
4. Apply WAF virtual patching to block LFI vectors until a vendor patch is released.
5. Harden site: enforce least privilege, disable file editing, restrict uploads, and enable 2FA.
6. Take backups and preserve logs for forensic analysis if necessary.
7. Monitor carefully for at least 30 days; attackers often return.

If you need assistance with incident response, containment, or forensic analysis, engage a reputable security or forensics provider experienced with WordPress incidents. Quick, measured action is what prevents a disclosed bug from becoming a full breach.