Atomic Edge analysis of CVE-2024-13362:
This vulnerability is a reflected DOM-based cross-site scripting (XSS) flaw in the Freemius SDK version 2.10.1, affecting various WordPress plugins and themes that bundle the SDK, including the Code Manager plugin. The flaw resides in the trial promotion notice feature, where the `trial_url` parameter is injected directly into HTML markup without output encoding. An unauthenticated attacker can craft a malicious URL that, when clicked by an administrator, executes arbitrary JavaScript in the browser context. The CVSS score is 6.1 (Medium), indicating a moderate severity reflected XSS.
Root Cause:
The root cause is in `code-manager/vendor/freemius/includes/class-freemius.php`, lines 24000-24020. The vulnerable code constructs an HTML anchor element by directly embedding the `$trial_url` variable into an `href` attribute via string interpolation: `’‘`. The `$trial_url` is passed as the first argument to `sprintf()`. No sanitization or output escaping (e.g., `esc_url()`, `esc_attr()`, `htmlspecialchars()`) is applied to `$trial_url` before it is placed into the HTML attribute. An attacker can control `$trial_url` via the `url` POST/GET parameter, which the `get_trial_url()` method (not shown in diff but referenced in code flow) reads. The resulting unsanitized string is then stored in a sticky admin notice and rendered in the admin dashboard.
Exploitation:
An attacker creates a specially crafted link to a page on the target WordPress site that triggers the trial promotion notice with a malicious `url` parameter. The attacker must trick an authenticated administrator into clicking the link. For example, the attacker could send: `https://target.com/wp-admin/admin.php?page=freemius-trial&url=javascript:alert(document.cookie)`. When the admin accesses this URL, the Freemius SDK processes the trial promotion logic and renders the admin notice. The `url` parameter is inserted into the `href` attribute without escaping, allowing a `javascript:` URI scheme. In a more subtle attack, the attacker could use an encoded payload: `https://target.com/wp-admin/admin.php?page=freemius-trial&url=%22%3E%3Cscript%3Ealert(1)%3C/script%3E`. This closes the anchor tag’s `href` and injects a script element directly into the DOM. The payload executes immediately because the browser parses the injected HTML. The attack does not require authentication; it only requires the victim to be authenticated and to click the crafted link.
Patch Analysis:
The patch in `class-freemius.php` changes the HTML structure from a raw anchor tag with an inline button to a container with a CSS-classed anchor. The key change is that the patched code wraps the entire notice in a `
Frequently Asked Questions
What is CVE-2024-13362?
Understanding the vulnerabilityCVE-2024-13362 is a reflected DOM-based cross-site scripting (XSS) vulnerability affecting the Freemius SDK version 2.10.1 and various WordPress plugins, including Code Manager. It allows unauthenticated attackers to inject arbitrary JavaScript into web pages by manipulating the ‘url’ parameter.
How does the vulnerability work?
Mechanism of exploitationThe vulnerability arises from insufficient input sanitization and output escaping of the ‘url’ parameter in the HTML markup. When an administrator clicks a crafted link containing a malicious URL, arbitrary JavaScript can execute in their browser, potentially compromising their session.
Who is affected by this vulnerability?
Identifying vulnerable usersWordPress administrators using the affected versions of the Freemius SDK and associated plugins such as Code Manager are at risk. To check if you are affected, verify if your version is 2.10.1 or earlier.
How can I check if my site is vulnerable?
Steps for vulnerability assessmentYou can check your site’s version of the Code Manager plugin and the Freemius SDK. If you are running version 1.0.40 or earlier, you are vulnerable to CVE-2024-13362.
What should I do to fix this vulnerability?
Recommended actionsTo mitigate the issue, update the Code Manager plugin to version 1.0.41 or later, which contains the patch for this vulnerability. Regularly check for updates to all plugins and themes to ensure security.
What does the CVSS score of 6.1 indicate?
Understanding severity levelsThe CVSS score of 6.1 classifies this vulnerability as medium severity. This means that while it is not the highest risk, it poses a significant threat to affected systems, particularly if exploited by an attacker.
What are the practical risks of this vulnerability?
Potential consequences of exploitationIf exploited, an attacker could execute arbitrary JavaScript in the context of the WordPress admin dashboard, leading to session hijacking, unauthorized actions, or content injection. The impact is particularly severe if an administrator is tricked into clicking a malicious link.
How does the proof of concept demonstrate the issue?
Example of exploitationThe proof of concept shows how an attacker can craft a URL that includes a malicious ‘url’ parameter. When an administrator accesses this URL, the injected JavaScript executes, demonstrating the vulnerability’s potential for exploitation.
What changes were made in the patch for this vulnerability?
Overview of the fixThe patch for CVE-2024-13362 restructures the HTML output to mitigate the XSS risk. It also introduces a filter for the message text to allow for proper escaping, although it does not directly escape the ‘url’ parameter, which is a partial mitigation.
What is reflected DOM-based XSS?
Defining the attack typeReflected DOM-based XSS is a type of cross-site scripting where the injected script is reflected off a web server and executed in the user’s browser. It typically requires user interaction, such as clicking a link, to trigger the attack.
How can I ensure my site is secure against future vulnerabilities?
Best practices for securityTo enhance security, regularly update all WordPress plugins and themes, use security plugins that monitor for vulnerabilities, and educate users about phishing and social engineering attacks.
What should I do if I suspect my site has been compromised?
Immediate response stepsIf you suspect a compromise, immediately change all administrator passwords, check for unauthorized user accounts, and review logs for suspicious activity. Consider restoring from a clean backup and conducting a full security audit.
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