CVE-2015-4582 is a high-severity cross-site scripting (XSS) vulnerability identified in TheCartPress boot-store WordPress theme version 1.6.4. Specifically, the vulnerability arises from improper neutralization of input during web page generation, classified under CWE-79. The flaw exists in the header.php file within the tcp_register_error functionality, where user-supplied input is not adequately sanitized or encoded before being rendered in the web page. This allows an attacker to inject malicious scripts that execute in the context of the victim's browser without requiring authentication or user interaction. The vulnerability has a CVSS 3.1 base score of 7.2, reflecting its network attack vector, low attack complexity, no privileges required, no user interaction, and a scope change with partial impact on confidentiality and integrity but no impact on availability. Exploitation could lead to theft of sensitive information such as cookies, session tokens, or other credentials, and potentially enable further attacks like session hijacking or defacement. Although no known exploits are currently reported in the wild, the vulnerability remains a significant risk due to the ease of exploitation and the widespread use of WordPress themes in e-commerce environments. No official patches or updates are currently linked for this specific theme version, increasing the urgency for mitigation.

For European organizations, especially those operating e-commerce platforms using WordPress with TheCartPress boot-store theme 1.6.4, this vulnerability could lead to unauthorized disclosure of sensitive customer data, including personal and payment information. This compromises confidentiality and integrity, potentially damaging customer trust and violating GDPR requirements for data protection. The scope change in the CVSS vector indicates that exploitation could affect components beyond the vulnerable theme, possibly impacting the entire website session or user accounts. The lack of required privileges and user interaction means attackers can remotely exploit the vulnerability without needing to trick users, increasing the risk of automated or large-scale attacks. This could result in reputational damage, financial losses from fraud, and regulatory penalties. Additionally, compromised sites could be used as vectors for further attacks against visitors or internal networks. Given the critical role of e-commerce in many European economies, the vulnerability poses a tangible threat to business continuity and data security.

1. Immediate removal or disabling of the TheCartPress boot-store theme version 1.6.4 from production environments until a secure update is available. 2. Implement Web Application Firewall (WAF) rules specifically targeting XSS payloads in HTTP headers and parameters associated with tcp_register_error to block malicious input. 3. Employ Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of potential XSS exploits. 4. Conduct thorough input validation and output encoding on all user-supplied data within custom themes or plugins, following OWASP guidelines. 5. Regularly audit WordPress themes and plugins for security updates and replace unsupported or unmaintained components. 6. Monitor web server logs for suspicious requests targeting header.php or tcp_register_error parameters to detect exploitation attempts early. 7. Educate development and security teams on secure coding practices to prevent similar vulnerabilities in custom WordPress themes. 8. Consider isolating e-commerce platforms in segmented network zones to limit lateral movement if compromise occurs.