CVE-2024-1859 Overview
The Slider Responsive Slideshow WordPress plugin by Awplife contains a PHP Object Injection vulnerability affecting all versions up to and including 1.3.8. The flaw stems from unsafe deserialization of untrusted input in the awl_slider_responsive_shortcode function. Authenticated attackers with contributor-level access or higher can inject arbitrary PHP objects into the application. The vulnerability itself does not ship with a Property Oriented Programming (POP) chain, but any additional plugin or theme on the target site can supply one. When a POP chain is available, attackers can delete arbitrary files, exfiltrate sensitive data, or achieve remote code execution. The issue is categorized under CWE-502 Deserialization of Untrusted Data.
Critical Impact
Authenticated contributors can inject PHP objects that, when combined with a POP chain from another installed component, lead to arbitrary file deletion, data disclosure, or remote code execution.
Affected Products
- Awplife Slider Responsive Slideshow plugin for WordPress, versions up to and including 1.3.8
- WordPress installations using the awl_slider_responsive_shortcode shortcode
- Sites where the plugin is combined with additional plugins or themes that expose usable POP chains
Discovery Timeline
- 2024-03-01 - CVE-2024-1859 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-1859
Vulnerability Analysis
The vulnerability resides in the awl_slider_responsive_shortcode function, which passes attacker-controllable input into PHP's unserialize() routine. PHP object deserialization reconstructs objects and invokes magic methods such as __wakeup, __destruct, or __toString on the resulting instances. When an attacker controls the serialized payload, they control which class is instantiated and which magic methods execute. The plugin itself does not contain gadget classes that can be chained into a harmful action. However, WordPress environments commonly load dozens of plugins and themes, many of which define classes with dangerous side effects in their magic methods. Once such a class is autoloaded in the same request, the attacker's serialized object triggers the chain during deserialization.
Root Cause
The root cause is direct use of unserialize() on data that originates from a shortcode attribute processed by an authenticated user. Input validation and type restrictions on the deserialized payload are absent, so any serialized PHP object is accepted. This is a textbook CWE-502 pattern where trust boundaries between low-privilege authenticated users and server-side execution context are not enforced.
Attack Vector
Exploitation requires an authenticated account with the contributor role or higher. The attacker submits post or page content that invokes the vulnerable shortcode with a crafted serialized PHP object as an attribute value. When the shortcode is rendered, unserialize() reconstructs the object and executes any magic methods defined by classes present in the runtime. Impact depends on which additional plugins or themes are installed, since they provide the gadgets used for file deletion, SQL exfiltration, or command execution. Refer to the Wordfence Vulnerability Report for additional technical context.
Detection Methods for CVE-2024-1859
Indicators of Compromise
- Post or page content authored by contributor-level accounts containing shortcode attributes with serialized PHP payloads beginning with O:, a:, or s: followed by class names.
- Unexpected file deletions, new PHP files in wp-content/uploads, or modified theme and plugin files following contributor content submissions.
- PHP error log entries referencing unserialize(), __wakeup, or __destruct from the Slider Responsive Slideshow plugin path.
Detection Strategies
- Inspect posts and custom fields for shortcodes invoking the Slider Responsive Slideshow plugin with attribute values that look like serialized PHP objects.
- Correlate WordPress audit logs with web server access logs to identify contributor accounts submitting encoded payloads to post.php or the REST API wp/v2/posts endpoint.
- Deploy web application firewall rules that flag serialized object patterns such as O:\d+:" inside shortcode attributes.
Monitoring Recommendations
- Alert on newly created or promoted contributor accounts, especially those authoring content that renders the vulnerable shortcode.
- Monitor filesystem integrity across wp-content/, wp-includes/, and wp-admin/ for unexpected deletions or modifications.
- Review outbound network connections from the PHP process for unusual destinations that could indicate data exfiltration via a POP chain.
How to Mitigate CVE-2024-1859
Immediate Actions Required
- Update the Slider Responsive Slideshow plugin to a version later than 1.3.8 immediately, using the fix delivered in WordPress Plugin Changeset 3041884.
- Audit all contributor, author, and editor accounts and disable any that are unused or unrecognized.
- Scan existing post content for serialized payloads in shortcode attributes and remove suspicious entries.
Patch Information
The vendor addressed the vulnerability in a release following 1.3.8. The fix is documented in the WordPress Plugin Changeset and validates or sanitizes input before it reaches deserialization logic. Administrators should apply the update through the WordPress plugin management interface or via WP-CLI.
Workarounds
- If patching is not immediately possible, deactivate and remove the Slider Responsive Slideshow plugin until the update is deployed.
- Restrict content creation privileges by removing the contributor role from untrusted users and requiring editor review before shortcode-bearing content is published.
- Deploy a web application firewall rule that blocks requests containing serialized PHP object patterns in shortcode attributes targeting the plugin.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
