Critical advisory — Silencesoft RSS Reader (<= 0.6) — CSRF allowing RSS feed deletion (CVE-2025-7842)

Published: 22 August 2025
Author: Hong Kong Security Expert

Short summary

A Cross-Site Request Forgery (CSRF) vulnerability has been reported in the Silencesoft RSS Reader / External RSS Reader WordPress plugin, affecting versions up to and including 0.6 (CVE-2025-7842). The flaw allows an attacker to trigger deletion of RSS feed entries or feed configurations if an authenticated user with sufficient privileges visits a malicious page. Public severity ratings classify this as low (CVSS 4.3), but the operational impact can be material for sites that rely on feed imports or automated publishing.

If the plugin is in use on production systems, treat this as time-sensitive and take conservative, immediate action.

What is the vulnerability?

Type: Cross-Site Request Forgery (CSRF)
Affected software: Silencesoft RSS Reader (External RSS Reader) plugin for WordPress
Vulnerable versions: <= 0.6
CVE: CVE-2025-7842

CSRF tricks an authenticated user into performing unintended actions by causing their browser to submit a request to the target site while they are still logged in. In this case, the plugin exposes a deletion action without adequate anti-CSRF protections (missing nonce verification and/or missing capability checks). An attacker can craft a request that, when executed by an admin’s browser, deletes feed configurations or imported entries.

While this does not enable remote code execution, it can remove content, break automated publishing workflows, and create operational outages.

How this typically works (technical explanation, non-exploitable)

WordPress plugins commonly implement admin actions through admin endpoints (admin-post.php, admin-ajax.php, or custom admin pages). Secure handlers must:

• Verify a WordPress nonce (wp_verify_nonce or check_admin_referer).
• Verify the current user has required capability (e.g., current_user_can(‘manage_options’)).
• Sanitize and validate inputs before acting.

A CSRF flaw exists where a destructive action is executed based solely on request parameters without nonce or capability checks. An attacker hosts a page that issues the deletion request; if an admin visits it while authenticated, their browser will send cookies and the plugin may delete the feed.

Exploitation requires social engineering to have an authenticated user visit an attacker-controlled page — a realistic risk via phishing or embedded content.

Real-world impact

• Deleted RSS feed configurations disrupt content import workflows and scheduled posts.
• Automated posting pipelines may fail until configurations are restored.
• Administrators might not notice deletions immediately, causing missed publications and operational issues.
• In high-volume or multi-site environments, recovery can be time-consuming and costly.
• Feed deletion can remove metadata and imported associations; recovery may require backups.

Operational and availability impacts can be significant despite the low CVSS score.

Who is at risk?

• Sites running Silencesoft RSS Reader / External RSS Reader plugin versions <= 0.6.
• Sites where an authenticated user with feed-management privileges (administrator, editor, or custom role) might visit untrusted web pages.
• Agencies or platforms that import feeds into many sites or run automated publishing tasks.

If unsure whether the plugin is installed, check WordPress admin > Plugins or search the filesystem for directories named external-rss-reader or silencesoft-rss-reader.

Immediate recommended actions (prioritised)

1. Inventory affected installations — search your WordPress sites and managed hosting panels for the plugin and confirm version <= 0.6.
2. Consider disabling or removing the plugin on production sites until a patch is available. If feeds are mission-critical, follow temporary mitigations below while preparing a safe restoration plan.
3. Restrict administrative access during remediation — reduce active admin sessions, require trusted staff to perform admin tasks, and enforce multi-factor authentication for high-privilege accounts.
4. Apply immediate network/application-level protections — if you operate a web application firewall (WAF) or reverse proxy, create rules to block suspicious POSTs to plugin endpoints or admin endpoints that lack valid nonces or originate from external referrers.
5. Monitor logs and audit — review POSTs to admin-ajax.php, admin-post.php, or plugin-specific admin URLs for parameters like action=delete_feed or feed_id around times when deletions occur.
6. Backup before remediation — take a full backup (files + database) before removing or modifying the plugin so you can recover feed records if needed.
7. When a patch is released — test on staging then update production promptly.

If you can’t disable the plugin: quick mitigations

• Add a temporary guard in the deletion handler — require a secret token, custom header, or verify a nonce and capability before proceeding (developer intervention required).
• Restrict access at server level — limit access to wp-admin or the plugin’s endpoints by IP using webserver rules or firewall controls.
• Block external origins — use .htaccess/Nginx rules to deny cross-origin POSTs to known plugin URLs if their paths are known.
• Role separation — remove unnecessary admin accounts and reduce the number of users with feed-management privileges.

Example temporary guard (developer intervention required)

<?php
// Example temporary guard (developer intervention required)
if ( ! current_user_can( 'manage_options' ) ) {
    wp_die( 'Insufficient permissions' );
}
if ( ! isset( $_POST['wpnonce'] ) || ! wp_verify_nonce( $_POST['wpnonce'], 'silencesoft_delete_feed' ) ) {
    wp_die( 'Missing or invalid nonce' );
}
?>
  

How developers should fix the vulnerability (for plugin maintainers)

Fixing destructive admin actions requires capability checks paired with proper nonces and robust input handling:

1. Enforce capability checks — use current_user_can() with the correct capability for the intended role.
2. Require and verify nonces — render wp_nonce_field() in admin forms and call check_admin_referer() or wp_verify_nonce() in handlers.
3. Use appropriate action endpoints — process admin requests through admin-post.php or admin-ajax.php with authenticated handlers and capability checks.
4. Sanitise and validate inputs — cast IDs to integers (absint()), verify existence before deletion, and log actions.
5. Consider origin checks — while WordPress nonces are usually sufficient, additional referer or Origin header checks add defence in depth.
6. Publish a security update — release a patch implementing these checks and notify users to update immediately.

Example secure deletion handler (simplified)

<?php
add_action( 'admin_post_silencesoft_delete_feed', 'silencesoft_handle_delete_feed' );
function silencesoft_handle_delete_feed() {
    if ( ! current_user_can( 'manage_options' ) ) {
        wp_die( 'Access denied' );
    }
    check_admin_referer( 'silencesoft_delete_feed_action' ); // verifies nonce sent with form
    $feed_id = isset( $_POST['feed_id'] ) ? absint( $_POST['feed_id'] ) : 0;
    if ( $feed_id ) {
         // verify feed exists, then delete
         silencesoft_delete_feed_by_id( $feed_id );
         wp_redirect( admin_url( 'admin.php?page=silencesoft-feeds&deleted=1' ) );
         exit;
    }
    wp_die( 'Invalid feed' );
}
?>
  

Example admin form with nonce

<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>">
    <?php wp_nonce_field( 'silencesoft_delete_feed_action' ); ?>
    <input type="hidden" name="action" value="silencesoft_delete_feed">
    <input type="hidden" name="feed_id" value="<?php echo esc_attr( $feed_id ); ?>">
    <button type="submit" class="button">Delete</button>
</form>
  

WAF rule examples and detection signatures (conceptual)

The following are conceptual rule ideas to implement in your WAF, reverse proxy or server configuration. Test any rule on staging to avoid blocking legitimate admin activity.

1. Block POSTs to plugin endpoints missing a WP nonce
   Pattern: POST requests to admin-ajax.php or admin-post.php containing parameter names like feed_id, delete_feed, or action values associated with the plugin, where the request does not include a valid nonce or lacks same-origin referer.
2. Block cross-origin form submissions to admin endpoints
   If a POST to /wp-admin/ or admin-ajax.php originates from an external origin (referer not same-origin), block or challenge.
3. Rate-limit suspicious POSTs
   Temporarily block or throttle IPs that issue repeated deletion-like requests against admin endpoints.

Conceptual pseudo-rule:

IF (REQUEST_METHOD == POST)
AND (REQUEST_URI contains "admin-ajax.php" OR "admin-post.php")
AND (REQUEST_BODY contains "action=silencesoft_delete_feed" OR parameter names "feed_id")
AND (HTTP_REFERER not same-origin OR X-WP-Nonce missing)
THEN block and log
  

Hardening best practices for WordPress administrators

• Minimise administrator accounts and use specific roles for content managers.
• Enforce multi-factor authentication for privileged accounts.
• Maintain regular backups (files + database) and verify restores periodically.
• Keep a plugin inventory and remove unused plugins.
• Enable integrity monitoring and security scans to detect unexpected changes.
• Review audit logs for unusual admin actions.
• Train staff to avoid visiting untrusted pages while logged into admin dashboards.

Recovery guidance if feeds were deleted

1. Restore from the most recent backup that predates the deletion.
2. If a full restore is not possible, restore the plugin-specific options or database table that stores feed records.
3. Manually recreate feed configurations and re-import content if needed; re-enable scheduled jobs.
4. Rotate credentials of administrative accounts that may have visited untrusted sites and review logs for signs of misuse.

How to detect if you were targeted or impacted

• Review activity logs and server access logs for POST requests to admin endpoints with parameters referencing “feed”, “delete”, “action=…” or feed IDs.
• Inspect the plugin’s storage (options table or custom tables) and compare against backups.
• Open the plugin admin UI and verify feed lists and import status.
• Check administrative notifications or plugin logs for deletion events.

If you find evidence of deletion, restore from backups and consider rotating administrative credentials for accounts that may have been exposed.

Detection rules to add to audit logging

• Log and alert on POSTs to admin-ajax.php or admin-post.php that result in deletion actions (capture action parameter values).
• Log when feed delete functions run via hooks and include the executing user and timestamp.
• Record user agent, referer, and origin headers on admin POSTs and alert when referer is off-site.

Why virtual patching (WAF) matters while waiting for a plugin fix

When a public disclosure precedes a vendor patch, there is a window of exposure. A properly configured WAF or reverse proxy can provide immediate protection without modifying plugin code:

• Block exploit attempts at the edge and buy time for a tested code fix.
• Reduce risk for production systems that cannot remove or disable the plugin immediately.

Virtual patching is a temporary, compensating control and must be used alongside code fixes and operational remediation.

Frequently asked questions (FAQ)

Q: Is CSRF the same as remote code execution?
A: No. CSRF causes a logged-in user to perform actions on the site; it typically does not permit arbitrary code execution. Still, CSRF can result in destructive changes and should be taken seriously.

Q: If only editors run imports, am I still at risk?
A: Yes. Any role with sufficient privileges to trigger the vulnerable action is at risk if a user with that role visits a malicious page.

Q: Will a WAF break legitimate feed management?
A: If rules are carefully scoped and tested, a WAF can block exploit-like requests while allowing legitimate admin actions. Always test in monitor mode before enforcing.

Incident response checklist (quick)

• Identify all sites with the vulnerable plugin.
• Snapshot and backup affected sites (files + DB).
• Disable or remove the plugin where feasible.
• If disabling is not an option, deploy targeted edge rules to block exploit patterns.
• Increase logging for admin endpoints and alert on suspicious activity.
• Notify admins to avoid logging in from untrusted networks or browsers until patched.
• Monitor for signs of malicious activity and restore deleted records from known-good backups.

Closing notes

Small development oversights — missing nonces or capability checks — routinely cause notable operational disruption. CSRF is preventable by following WordPress security practices: verify nonces, enforce capability checks, and sanitise inputs. Operators should prioritise inventory, minimise privileges, and assume attackers may attempt social-engineering vectors.

If you manage sites using Silencesoft RSS Reader / External RSS Reader plugin (≤ 0.6), assume immediate action is required: at minimum restrict admin access and apply mitigations while awaiting an official plugin update. If you maintain plugins, implement nonce verification and capability checks and publish a patch without delay.

Appendix — quick reference

• Vulnerability: Silencesoft RSS Reader (External RSS Reader) ≤ 0.6 — CSRF to RSS feed deletion
• CVE: CVE-2025-7842
• Risk: Low severity (CVSS 4.3) but operationally disruptive
• Immediate steps: inventory, backup, disable/remove plugin or deploy edge virtual patch, restrict admin access, monitor logs
• Developer fix: add capability checks, verify nonces, sanitise inputs, release patch promptly