Description

Deserialization of Untrusted Data vulnerability in ThemeREX Group Smash smash allows Object Injection.This issue affects Smash: from n/a through 1.12.0.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-10T08:17:05.427Z",
  "pubdate": "2026-10-10T08:17:05.427Z",
  "executiveSummary": "The Smash plugin by ThemeREX Group is susceptible to an Object Injection vulnerability due to the insecure deserialization of untrusted input.\nThis vulnerability is categorized as a Deserialization of Untrusted Data flaw, which allows unauthenticated or authenticated attackers to supply malicious serialized objects to the application.\nSuccessful exploitation enables remote code execution, unauthorized file system access, or significant disruption of service by manipulating application logic via injected object properties.\nThe vulnerability affects the Smash plugin for versions from n/a through 1.12.0.\nThe risk implication is critical, as it bypasses standard input validation mechanisms, allowing for complete system compromise if the server environment contains exploitable gadget chains.\nAttackers can leverage this vulnerability to instantiate arbitrary classes within the PHP object scope, leading to unexpected state changes or the execution of arbitrary code within the context of the web server process.\nImmediate remediation is required, as the lack of object type validation provides a direct vector for code execution without the need for sophisticated bypass techniques.",
  "technicalDetails": "The Smash plugin exhibits a critical security flaw rooted in the improper handling of serialized data passed via user-controlled input vectors. The application fails to implement adequate validation or sanitization before passing this data to PHP's unserialize() function.\nObject Injection occurs when an application deserializes untrusted data that contains malicious object definitions. In PHP, this process triggers the magic methods of the serialized class, such as __wakeup(), __destruct(), or __toString(). An attacker can leverage these magic methods—often referred to as 'gadgets'—within the application's codebase or included libraries to manipulate the application state.\nThe attack flow begins with the identification of an endpoint or parameter that accepts serialized input. An attacker crafts a malicious serialized payload designed to hijack the flow of execution. Upon reaching the unserialize() call, the PHP engine instantiates the attacker-supplied object structure. If the target environment contains a gadget chain, the attacker can influence the behavior of the application by controlling the properties of these instantiated objects.\nSpecifically, the vulnerability allows an attacker to control the internal properties of objects that are reconstructed in memory. By carefully selecting which classes to instantiate, an attacker can trigger unintended functionality, such as arbitrary file deletion, modification of local configuration files, or remote code execution. This is possible because the vulnerability grants the attacker the ability to inject custom data structures that the plugin subsequently processes, processes as trusted application logic.\nThis vulnerability is particularly severe because it does not rely on traditional SQL injection or XSS patterns, but rather exploits the fundamental way the plugin handles object serialization. Given that this affects Smash versions from n/a through 1.12.0, the attack surface is wide for any site running these versions of the plugin. The exploitation is typically performed over the network via standard HTTP request parameters or cookies that the plugin processes. Once the object is injected, the payload's behavior is limited only by the available classes and methods within the WordPress environment and the underlying PHP stack. Post-exploitation, an attacker may achieve persistent access, elevate privileges, or perform data exfiltration by effectively hijacking the execution context of the server."
}