CVE-2024-52415: SK WP Settings Backup CSRF Vulnerability

CVE-2024-52415 Overview

CVE-2024-52415 is a Cross-Site Request Forgery (CSRF) vulnerability in the SK WP Settings Backup WordPress plugin developed by skipstorm. The flaw affects all versions up to and including 1.0. When a victim with sufficient privileges visits a malicious page, an attacker can trigger plugin actions that lead to PHP Object Injection. The chain combines a missing CSRF token check [CWE-352] with unsafe deserialization of attacker-controlled input. Successful exploitation can compromise confidentiality, integrity, and availability of the affected WordPress site.

Critical Impact
A remote attacker can coerce an authenticated administrator into submitting a forged request that triggers PHP Object Injection, enabling code execution paths dependent on available POP gadgets in the WordPress environment.

Affected Products

skipstorm SK WP Settings Backup plugin for WordPress
All versions through 1.0
WordPress sites with the sk-wp-settings-backup plugin installed and active

Discovery Timeline

2024-11-16 - CVE-2024-52415 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2024-52415

Vulnerability Analysis

The vulnerability combines two weaknesses into a single exploit chain. The plugin's settings backup and restore functionality does not validate CSRF tokens (nonces) on state-changing requests. The same handler subsequently deserializes user-supplied data without validating its structure or origin. An attacker who hosts a crafted page can submit a forged form to a logged-in administrator's browser. The resulting request invokes unserialize() on attacker-controlled input, instantiating arbitrary PHP objects in the WordPress runtime.

The impact depends on classes loaded by WordPress core, the active theme, and other plugins. Many WordPress installations expose property-oriented programming (POP) gadget chains that lead to arbitrary file writes, file deletion, or remote code execution when triggered through deserialization.

Root Cause

The root cause is the absence of a WordPress nonce verification call such as check_admin_referer() or wp_verify_nonce() on the plugin's backup/restore endpoints [CWE-352]. The handler then passes untrusted POST data to PHP's unserialize() function instead of using a safe format such as JSON. This pattern matches CWE-502 (Deserialization of Untrusted Data) reachable through the CSRF primitive.

Attack Vector

Exploitation requires user interaction from an authenticated administrator. The attacker delivers a malicious link or embeds a crafted form on a controlled site. When the administrator visits the page, the browser submits the forged request to the vulnerable plugin endpoint, carrying the administrator's session cookie. The plugin processes the request and deserializes the supplied payload, triggering the object injection. No prior authentication on the attacker side is required, and the attack is delivered over the network.

No public proof-of-concept code is referenced in the advisory. Technical details are available in the Patchstack advisory.

Detection Methods for CVE-2024-52415

Indicators of Compromise

Unexpected POST requests to plugin endpoints under /wp-admin/ or /wp-content/plugins/sk-wp-settings-backup/ originating from external referrers
Serialized PHP payloads in request bodies containing patterns such as O: (object), a: (array), or known gadget class names
Newly created administrator accounts, modified plugin or theme files, or unexpected scheduled tasks following plugin activity
Outbound connections from the web server process to attacker-controlled infrastructure after a suspicious admin browsing session

Detection Strategies

Inspect web server access logs for POST requests to the plugin's admin handlers with Referer headers pointing to untrusted domains
Deploy web application firewall rules that flag serialized PHP object markers in request parameters destined for WordPress endpoints
Correlate administrator session activity with file integrity changes in wp-content/ to identify deserialization-driven file writes
Alert on PHP processes spawning shells or invoking outbound network calls during plugin request handling

Monitoring Recommendations

Enable WordPress audit logging for plugin settings changes, option updates, and user role modifications
Forward web server, PHP-FPM, and WordPress audit logs to a centralized SIEM for correlation
Monitor for installation or activation of sk-wp-settings-backup across managed WordPress fleets
Track EPSS movement and vendor advisories for any reissued or chained exploitation reports

How to Mitigate CVE-2024-52415

Immediate Actions Required

Deactivate and remove the SK WP Settings Backup plugin from all WordPress installations until a fixed version is released
Audit administrator accounts for unauthorized additions and rotate credentials for all privileged users
Review wp-content/ directories for unexpected file modifications, web shells, or new scheduled tasks
Force re-authentication of all administrative sessions to invalidate any tokens captured during exploitation

Patch Information

No patched version is identified in the advisory. The vulnerability affects SK WP Settings Backup from initial release through version 1.0, and no fixed release is listed by the vendor. Refer to the Patchstack vulnerability database entry for the latest status.

Workarounds

Remove the plugin entirely; this is the most reliable mitigation while no patch exists
Restrict access to /wp-admin/ by source IP using web server controls or a reverse proxy
Deploy a web application firewall rule that blocks requests containing serialized PHP object markers targeting plugin endpoints
Require administrators to use isolated browsers or dedicated admin workstations to reduce CSRF exposure from general browsing

bash

# Example: remove the vulnerable plugin via WP-CLI
wp plugin deactivate sk-wp-settings-backup
wp plugin delete sk-wp-settings-backup

# Example: nginx rule to block serialized PHP payloads to plugin path
location ~ /wp-content/plugins/sk-wp-settings-backup/ {
    if ($request_body ~* "(^|&)[^=]+=O:[0-9]+:\"") {
        return 403;
    }
}