CVE-2023-0559 in GS Portfolio for Envato Plugin
Summary
by MITRE • 02/21/2023
The GS Portfolio for Envato WordPress plugin before 1.4.0 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embedded, 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 • 03/23/2023
The vulnerability identified as CVE-2023-0559 affects the GS Portfolio WordPress plugin version 1.4.0 and earlier, presenting a critical security risk through stored cross-site scripting flaws. This issue stems from inadequate input validation and output escaping mechanisms within the plugin's shortcode implementation, creating an attack vector that can be exploited by users holding contributor-level privileges or higher. The vulnerability manifests when the plugin processes shortcode attributes without proper sanitization, allowing malicious code to be stored within the WordPress database and subsequently executed whenever the affected content is rendered. The security implications extend beyond simple XSS attacks as this flaw enables attackers to potentially escalate privileges, steal user sessions, or redirect victims to malicious sites.
The technical flaw resides in the plugin's failure to properly validate and escape shortcode parameters before incorporating them into HTML output contexts. According to CWE-79, this represents a classic stored cross-site scripting vulnerability where malicious input is first stored in the database and then executed during subsequent page requests. The vulnerability specifically impacts the plugin's shortcode handling mechanism, which processes user-provided attributes without adequate sanitization. Attackers can leverage this weakness by injecting malicious JavaScript code through the shortcode attributes, which then gets stored in the WordPress database. When other users view pages containing the affected shortcode, their browsers execute the stored malicious code, potentially leading to session hijacking, credential theft, or redirection to phishing sites. This vulnerability directly maps to ATT&CK technique T1059.007 for JavaScript execution and T1546.001 for privilege escalation through web application vulnerabilities.
The operational impact of CVE-2023-0559 is significant for WordPress sites utilizing the affected GS Portfolio plugin, particularly those with multiple contributors or users who can publish content. The vulnerability allows attackers to gain persistent access to compromised sites through stored XSS, enabling them to execute arbitrary code in the context of victim browsers. This can result in complete compromise of user sessions, data exfiltration, and potential lateral movement within the WordPress environment. Organizations may experience reputational damage, regulatory compliance violations, and potential legal consequences due to data breaches facilitated by this vulnerability. The attack surface expands when considering that contributors and above can exploit this flaw, meaning that even sites with limited user permissions may be vulnerable to exploitation by insiders or compromised accounts. The stored nature of the vulnerability means that malicious payloads persist even after the initial attack, creating ongoing security risks that can compound over time.
Mitigation strategies for CVE-2023-0559 primarily focus on immediate plugin updates to version 1.4.0 or later, which contain the necessary patches to address the input validation and output escaping deficiencies. System administrators should implement comprehensive security monitoring to detect potential exploitation attempts and establish regular vulnerability scanning procedures for WordPress installations. The remediation process involves not only updating the plugin but also reviewing all existing shortcode usage within the WordPress environment to identify and sanitize any potentially compromised content. Security hardening measures should include implementing content security policies to limit script execution, restricting user capabilities through role-based access controls, and establishing proper input validation for all user-provided content. Organizations should also consider implementing web application firewalls to detect and block malicious payloads targeting this specific vulnerability. Additionally, regular security audits of WordPress plugins and themes should be conducted to ensure all components maintain current security standards and to prevent similar vulnerabilities from emerging in other parts of the WordPress ecosystem.