Description

Deserialization of Untrusted Data vulnerability in ThemeREX Group Rosalinda rosalinda allows Object Injection.This issue affects Rosalinda: from n/a through 1.2.4.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-10T08:17:05.680Z",
  "pubdate": "2026-10-10T08:17:05.680Z",
  "executiveSummary": "The Rosalinda theme for WordPress, developed by ThemeREX Group, contains a critical Deserialization of Untrusted Data vulnerability. This flaw allows remote, unauthenticated attackers to perform PHP object injection, potentially leading to Remote Code Execution (RCE), arbitrary file deletion, or sensitive data disclosure.\nThe vulnerability originates from the improper handling of serialized user-provided input, which is processed by the theme without adequate validation or sanitization. By injecting specially crafted serialized objects into the application, an attacker can manipulate the internal state of the application or trigger gadget chains within the theme's codebase or the wider WordPress environment.\nThis vulnerability affects Rosalinda versions from n/a through 1.2.4. Successful exploitation requires no authentication, allowing adversaries to execute arbitrary PHP functions or classes already present in the application scope. Given the nature of object injection, this vulnerability poses a significant risk to the integrity, confidentiality, and availability of the affected WordPress installation.\nSecurity teams should prioritize updating or restricting access to the affected theme functionality immediately to mitigate the risk of unauthorized server-side execution.",
  "technicalDetails": "The root cause of this vulnerability is the application of the PHP 'unserialize()' function on unsanitized user-supplied data. In the context of the Rosalinda theme, the application accepts serialized inputs—frequently passed via HTTP parameters or cookie values—and passes them directly to an unserialization routine without verification.\nThe attack flow begins when an attacker identifies an endpoint or script within the Rosalinda theme that performs an unserialize operation on input controlled by the user. The attacker then constructs a malicious serialized payload representing a specific PHP class present in the theme or the WordPress core. By carefully selecting these classes (often referred to as 'gadgets'), the attacker can manipulate existing class properties or trigger magic methods, such as '__wakeup()', '__destruct()', or '__toString()', during the deserialization process.\nUpon processing the malicious payload, the PHP engine automatically invokes these magic methods. If an attacker identifies a gadget chain—a sequence of method calls that lead to a dangerous sink—they can achieve arbitrary code execution. For instance, an object might trigger a file deletion method or a database query function using properties defined by the attacker during the injection process.\nBecause the theme does not implement object-level validation, the application environment blindly trusts the structure of the incoming data stream. The vulnerability is exploitable over the network without requiring any authentication, making it a high-severity threat. The impact is not limited to the theme itself; because the theme executes within the WordPress framework, the injected objects can leverage any available classes loaded in the current PHP execution context.\nPost-exploitation, an attacker can escalate privileges, execute arbitrary system commands, or modify site configurations to maintain persistence. The scope of the vulnerability includes all versions up to and including 1.2.4. The absence of a WAF (Web Application Firewall) rule specifically tailored to detect serialized payloads in the Rosalinda theme increases the likelihood of successful exploitation."
}