CVE-2023-0375 in Easy Affiliate Links Plugin
Summary
by MITRE • 02/21/2023
The Easy Affiliate Links WordPress plugin before 3.7.1 does not validate and escape some of its block options before outputting them back in a page/post where the block 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 • 03/12/2025
The vulnerability identified as CVE-2023-0375 affects the Easy Affiliate Links WordPress plugin, specifically versions prior to 3.7.1, presenting a critical security risk through stored cross-site scripting attacks. This flaw exists within the plugin's handling of block options where insufficient validation and escaping mechanisms allow malicious input to be persistently stored and subsequently executed within user browsers. The vulnerability is particularly concerning because it targets users with the contributor role and above, expanding the potential attack surface beyond typical administrative privileges. The issue manifests when block options are processed and output back into pages or posts where the block is embedded, creating a persistent vector for malicious code injection.
The technical implementation of this vulnerability stems from inadequate input sanitization within the plugin's block processing functionality. When contributors or higher-privileged users create or modify affiliate link blocks, the plugin fails to properly validate and escape user-supplied data before rendering it in the frontend output. This creates a classic stored XSS scenario where malicious scripts can be injected into block options and subsequently executed whenever the affected page is viewed. The vulnerability directly maps to CWE-79 - Cross-site Scripting and aligns with ATT&CK technique T1566.001 - Phishing, as it enables attackers to craft malicious content that can be delivered to unsuspecting users through legitimate plugin functionality. The flaw demonstrates poor secure coding practices in data validation and output escaping, which are fundamental requirements for preventing XSS attacks in web applications.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to perform various malicious activities through compromised user sessions. An attacker with contributor privileges can inject malicious JavaScript that could steal cookies, session tokens, or perform unauthorized actions on behalf of authenticated users. The persistent nature of stored XSS means that once the malicious payload is injected, it will continue to execute for all users who view the affected pages until the vulnerability is patched. This creates a significant risk for websites using the Easy Affiliate Links plugin, particularly those with multiple contributors or users who may inadvertently interact with malicious content. The vulnerability could also enable attackers to redirect users to malicious sites, harvest sensitive information, or manipulate the website's content to spread further attacks.
Mitigation strategies for CVE-2023-0375 should prioritize immediate patching of the Easy Affiliate Links plugin to version 3.7.1 or later, which addresses the validation and escaping deficiencies. System administrators should also implement additional security measures including restricting contributor privileges where possible, implementing content security policies to limit script execution, and monitoring for suspicious block modifications. The WordPress security community should consider implementing automated scanning tools to detect similar vulnerabilities in other plugins and themes. Organizations should conduct thorough security audits of their WordPress installations to identify any other potential XSS vulnerabilities that may exist due to similar input handling issues. Regular security updates and patch management processes should be enforced to prevent exploitation of known vulnerabilities, while also implementing proper input validation and output escaping mechanisms across all plugin and theme development. The vulnerability highlights the importance of following secure coding practices and adhering to industry standards such as those defined in the OWASP Top Ten and NIST cybersecurity guidelines for web application security.