Description

Deserialization of Untrusted Data vulnerability in ThemeREX Group Partiso partiso allows Object Injection.This issue affects Partiso: from n/a through 1.1.13.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-10T08:17:05.810Z",
  "pubdate": "2026-10-10T08:17:05.810Z",
  "executiveSummary": "The ThemeREX Group Partiso theme is susceptible to a Deserialization of Untrusted Data vulnerability, categorized as an Object Injection flaw.\nThis vulnerability exists in all versions of Partiso from n/a through 1.1.13.\nThe vulnerability allows an unauthenticated or remote attacker to inject malicious serialized objects into the application, which are subsequently deserialized without adequate validation.\nSuccessful exploitation can result in significant security compromises, including Remote Code Execution (RCE), unauthorized file manipulation, or denial of service, depending on the available PHP gadgets within the application environment.\nThe primary risk stems from the application's failure to sanitize user-supplied input before passing it to deserialization functions, effectively delegating control of the object lifecycle to an untrusted actor.\nAttackers can leverage this flaw to execute arbitrary code or bypass security controls by manipulating the state and properties of deserialized objects.\nOrganizations using the affected software are at high risk until the underlying deserialization mechanism is secured or the software is updated to a patched version.",
  "technicalDetails": "The vulnerability originates from the insecure implementation of PHP's unserialize() function or a similar deserialization routine within the Partiso theme. In PHP, the deserialization of untrusted data is inherently dangerous if the application contains 'gadget chains'—existing classes that perform sensitive operations (such as file I/O, database queries, or command execution) within their magic methods, specifically __wakeup(), __destruct(), or __toString().\nThe attack flow begins when an attacker identifies an entry point—typically a web request parameter or cookie—that accepts serialized PHP data as input. By crafting a malicious payload containing a chain of serialized objects, the attacker influences the execution flow of the application upon the call to the deserialization function.\nWhen the application deserializes the attacker-controlled input, it instantiates the objects specified in the payload. If these objects match classes currently defined in the application's scope, the PHP engine invokes the associated magic methods. An attacker with knowledge of the codebase can select specific classes to trigger unintended side effects, such as overwriting critical configuration variables, initiating unauthorized database transactions, or invoking system-level commands through backticks or exec() calls embedded in class properties.\nBecause this vulnerability occurs during the object instantiation phase, the application does not necessarily require the execution of specific business logic after deserialization to succeed; the mere act of creating the object with manipulated properties is sufficient to trigger the malicious logic contained within the class definition.\nThe impact of this vulnerability is profound. By leveraging the application's own code against itself, an attacker can achieve Remote Code Execution (RCE) with the privileges of the web server process. This allows for total system compromise, including the exfiltration of sensitive configuration data (like database credentials in wp-config.php), modification of the WordPress database, and potential lateral movement within the hosting environment.\nThe vulnerability affects all Partiso versions through 1.1.13. Exposure is high, as these entry points are typically reachable via standard HTTP requests without the need for prior authentication or elevated privileges, provided the endpoint accepting the input is exposed to the internet."
}