CVE-2023-0063 in Shortcodes Plugin
Summary
by MITRE • 03/06/2023
The WordPress Shortcodes WordPress plugin through 1.6.36 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.
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Analysis
by VulDB Data Team • 03/31/2023
The vulnerability identified as CVE-2023-0063 affects the WordPress Shortcodes plugin version 1.6.36 and earlier, presenting a critical security risk through stored cross-site scripting flaws. This issue specifically targets the plugin's handling of shortcode attributes within WordPress content management systems, creating an avenue for malicious actors to inject persistent malicious scripts into web pages. The vulnerability exists because the plugin fails to properly validate and escape user-supplied attributes before rendering them back into the HTML output, allowing attackers to exploit this weakness through the WordPress administrative interface.
The technical flaw manifests in the plugin's insufficient input sanitization mechanisms, where shortcode attributes are directly incorporated into the generated HTML without proper HTML escaping or validation procedures. This weakness enables attackers with contributor-level privileges or higher to inject malicious JavaScript code through shortcode parameters, which then gets stored in the WordPress database and executed whenever the affected page or post is rendered. The vulnerability operates under CWE-79 which classifies improper neutralization of input during web page generation, specifically focusing on cross-site scripting attacks. The stored nature of this vulnerability means that the malicious payload persists even after the initial injection, making it particularly dangerous as it can affect multiple users who view the compromised content.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to perform various malicious activities including session hijacking, credential theft, and redirection to malicious websites. Attackers can leverage this weakness to compromise user sessions, steal administrative privileges, or manipulate content displayed to other users. The vulnerability affects the core WordPress functionality by undermining the security boundaries between different user roles, as it allows lower-privilege users to potentially escalate their access or cause widespread disruption. This represents a significant concern for WordPress installations where multiple contributors or authors have access to the administrative interface, as these users could inadvertently or maliciously introduce persistent malicious code that affects all visitors to the site.
Mitigation strategies for this vulnerability should include immediate plugin updates to version 1.6.37 or later, which contain the necessary patches to address the input validation and output escaping issues. Organizations should also implement additional security measures such as regular security audits of installed plugins, monitoring for suspicious shortcode usage, and implementing content security policies to limit the impact of potential XSS attacks. The ATT&CK framework categorizes this vulnerability under T1548.003 which involves abuse of credentials and session management, while also relating to T1190 which covers exploitation of vulnerabilities in web applications. Administrators should also consider implementing web application firewalls, restricting plugin installation privileges, and conducting regular security training for users with contributor-level access to minimize the risk of exploitation.