CVE-2023-0538 in Campaign URL Builder Plugin
Summary
by MITRE • 03/13/2023
The Campaign URL Builder WordPress plugin before 1.8.2 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 • 03/18/2023
The vulnerability identified as CVE-2023-0538 affects the Campaign URL Builder WordPress plugin, specifically versions prior to 1.8.2, presenting a critical security risk through stored cross-site scripting attacks. This issue stems from insufficient input validation and output escaping mechanisms within the plugin's shortcode implementation, creating a persistent security weakness that can be exploited by authenticated users.
The technical flaw manifests in the plugin's failure to properly sanitize shortcode attributes before rendering them within web pages. When users with contributor privileges or higher insert campaign URLs using the plugin's shortcode functionality, the system does not adequately validate or escape the input parameters. This omission allows malicious actors to inject malicious scripts that persist in the database and execute whenever the affected page is loaded, creating a stored XSS vulnerability. The vulnerability specifically impacts the plugin's shortcode processing logic where user-supplied attributes are directly incorporated into HTML output without proper sanitization.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. Contributors and higher-privileged users can leverage this weakness to inject persistent malicious code that affects all visitors to pages containing the compromised shortcode. The vulnerability is particularly concerning because it requires minimal privileges to exploit, making it accessible to users who typically have limited administrative capabilities. This creates a significant risk for WordPress sites where content contributors have access to the platform, as they can inadvertently or maliciously introduce persistent threats that compromise the entire site's security posture.
The vulnerability aligns with CWE-79, which describes Cross-Site Scripting flaws, and represents a classic case of stored XSS where malicious input is permanently stored and executed. From an ATT&CK framework perspective, this vulnerability maps to T1566.001 (Phishing with Social Engineering) and T1059.001 (Command and Scripting Interpreter), as attackers can use the stored XSS to redirect users to malicious sites or execute commands through browser-based attacks. Organizations should prioritize immediate remediation by updating to version 1.8.2 or later, implementing additional input validation measures, and monitoring for suspicious shortcode usage patterns to prevent exploitation attempts.
Mitigation strategies should include immediate plugin updates, implementation of web application firewalls to detect and block suspicious script injections, and comprehensive security auditing of all plugin shortcode implementations. Regular security assessments should verify that all WordPress plugins properly sanitize user inputs and escape output to prevent similar vulnerabilities from being introduced through third-party components. Additionally, implementing role-based access controls and monitoring user activities can help detect potential exploitation attempts before they cause significant damage to the website's security infrastructure.