CVE-2024-13899 Overview
CVE-2024-13899 is a PHP Object Injection vulnerability in the Mambo Importer plugin for WordPress, affecting all versions up to and including 1.0. The flaw resides in the fImportMenu function, which deserializes untrusted input passed through the $data parameter. Authenticated attackers holding Administrator-level access or higher can inject arbitrary PHP objects into the application. The vulnerable plugin does not itself contain a Property-Oriented Programming (POP) chain, so exploitation depends on another installed plugin or theme providing a usable gadget chain. When a POP chain is available, attackers can delete arbitrary files, retrieve sensitive data, or execute code on the target site.
Critical Impact
Authenticated administrators can inject PHP objects that, when combined with a POP chain from another installed component, enable arbitrary file deletion, sensitive data disclosure, or remote code execution.
Affected Products
- Misterpah Mambo Joomla Importer plugin for WordPress
- All versions up to and including 1.0
- WordPress sites with additional plugins or themes containing POP chains
Discovery Timeline
- 2025-02-22 - CVE-2024-13899 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-13899
Vulnerability Analysis
The Mambo Importer plugin passes attacker-controlled data into PHP's unserialize() routine without validation. This condition is classified under [CWE-502] Deserialization of Untrusted Data. The vulnerability requires an authenticated session with Administrator privileges or higher, which limits opportunistic exploitation but remains significant in multi-administrator environments, compromised admin accounts, or scenarios involving privilege escalation from a lower role.
Because the plugin ships without an internal POP chain, exploitation is only impactful when another plugin or theme installed on the WordPress instance introduces classes with exploitable magic methods such as __destruct, __wakeup, or __toString. WordPress environments frequently contain dozens of plugins, which materially increases the probability that a usable gadget chain is present. Successful chained exploitation can lead to arbitrary file deletion, extraction of sensitive configuration data such as database credentials, or execution of arbitrary PHP code within the web server context.
Root Cause
The root cause is the direct deserialization of untrusted input inside the fImportMenu function through the $data parameter. The plugin accepts serialized PHP data from an authenticated request handler and passes it to unserialize() without type constraints, input validation, or use of the allowed_classes option. Any attacker able to reach the import endpoint with valid administrator credentials controls the object graph reconstructed by the PHP interpreter.
Attack Vector
The attack is network-reachable and requires high privileges but no user interaction. An authenticated administrator submits a crafted serialized payload to the Mambo Importer endpoint that invokes fImportMenu. The PHP interpreter reconstructs the attacker's object graph, and magic methods on gadget classes from other installed components execute as objects are instantiated or destroyed. The attacker chains these gadgets to reach dangerous sinks such as file operations, database queries, or code evaluation.
Refer to the WordPress Plugin Code Review and the Wordfence Vulnerability Report for the vulnerable code location and disclosure details.
Detection Methods for CVE-2024-13899
Indicators of Compromise
- HTTP POST requests to Mambo Importer administrative endpoints containing serialized PHP payloads beginning with O: or a: in the data parameter.
- Unexpected file deletions, new PHP files in the WordPress webroot, or modifications to wp-config.php following administrator activity involving the plugin.
- PHP error log entries referencing unserialize(), __wakeup, or __destruct calls originating from mamboImporter.php.
Detection Strategies
- Inspect web server access logs for authenticated admin requests to the Mambo Importer endpoint carrying serialized object markers in POST bodies.
- Deploy a Web Application Firewall (WAF) rule to flag or block serialized PHP payloads submitted to the plugin's import routes.
- Perform file integrity monitoring against WordPress core, plugin, and theme directories to identify unauthorized additions, deletions, or modifications.
Monitoring Recommendations
- Alert on the creation of PHP web shells or writes to wp-content/uploads originating from the web server process.
- Track administrator authentication anomalies, including new admin accounts, session activity from unfamiliar IP addresses, and password resets.
- Correlate PHP fatal error events with subsequent outbound network connections from the web server to catch chained code execution.
How to Mitigate CVE-2024-13899
Immediate Actions Required
- Deactivate and remove the Mambo Importer plugin from any WordPress installation running version 1.0 or earlier until a fixed release is published.
- Audit the WordPress administrator account list and revoke access for any account that is not strictly required.
- Enforce multi-factor authentication (MFA) on all Administrator-level accounts to reduce the risk of credential-based exploitation.
Patch Information
No vendor patch is referenced in the enriched CVE data. Because the plugin is vulnerable in all versions up to and including 1.0 and no fixed release is listed, uninstalling the plugin is the recommended remediation. Monitor the Wordfence Vulnerability Report for updates on a patched version.
Workarounds
- Remove the Mambo Importer plugin entirely; this is the most reliable mitigation given the absence of a vendor fix.
- Restrict administrative access to trusted IP ranges using web server ACLs or WordPress plugins that limit wp-admin reachability.
- Audit installed plugins and themes for classes containing dangerous magic methods and remove unused components to reduce available POP gadget chains.
- Configure a WAF policy to block requests containing PHP serialized object patterns targeting the plugin's endpoints.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
