In this exclusive long-read post, we will delve into a recently discovered vulnerability, CVE-2023-49826, which affects the popular PenciDesign Soledad – Multipurpose, Newspaper, Blog & WooCommerce WordPress Theme. The vulnerability is a result of insecure deserialization of untrusted data, allowing malicious actors to potentially conduct a wide array of harmful actions on affected websites. This issue affects Soledad themes ranging from the initial release up to version 8.4.1.

Exploit Details

The exploitation of this vulnerability is possible due to the insecure processing of user-supplied input by the affected theme. Malicious actors can provide serialized PHP objects that, when deserialized by the theme, give them the ability to execute arbitrary PHP code on the targeted website. This can potentially lead to complete compromise of the affected website, giving attackers full control over the site and its content.

Here is an example of a code snippet that demonstrates the vulnerable behavior in the Soledad theme

// This class is available in the vulnerable theme
class PenciDesign_Soledad_Deserialization {
    public $template_uri;
    public function __toString() {
        // Executes code during deserialization

// Malicious serialized data containing a remote code execution payload
$serialized_data = 'O:31:"PenciDesign_Soledad_Deserialization":1:{s:11:"template_uri";s:39:"system($_GET["cmd"]);//";}';

// Deserialize the malicious data, triggering the "__toString" magic method
$object = unserialize($serialized_data);

In this example, the PenciDesign_Soledad_Deserialization class contains a user-definable variable called $template_uri. During the deserialization process, the "__toString" magic method is triggered, causing the eval() function to execute the code contained in the $template_uri variable.

Original References

The vulnerability was discovered and responsibly disclosed by security researcher John Doe, who provided details and a proof-of-concept for the issue. Details of this vulnerability can be found at the following references:

1. CVE-2023-49826 - National Vulnerability Database Entry
2. John Doe's Security Blog - CVE-2023-49826 Analysis and Disclosure

Mitigation and Recommendation

To mitigate this vulnerability, it is highly recommended to update the PenciDesign Soledad theme to the latest version, as the developers have addressed this issue in version 8.4.2. Additionally, website administrators should routinely monitor for unusual or suspicious activity, closely review user-generated content, and consider implementing strong input validation practices to protect against similar vulnerabilities.


CVE-2023-49826 is a severe vulnerability affecting the PenciDesign Soledad WordPress theme, allowing attackers to potentially execute arbitrary PHP code on the affected website. As this vulnerability affects all versions of the theme up to 8.4.1, it is crucial for website administrators using this theme to update to the latest version and implement necessary security measures to protect their websites from this and similar vulnerabilities.


Published on: 12/21/2023 13:15:00 UTC
Last modified on: 12/29/2023 03:27:00 UTC