CVE-2023-48765 in Email Address Encoder Plugin
Summary
by MITRE • 12/15/2023
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Till Krüss Email Address Encoder allows Stored XSS.This issue affects Email Address Encoder: from n/a through 1.0.22.
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Analysis
by VulDB Data Team • 01/11/2024
The CVE-2023-48765 vulnerability represents a critical cross-site scripting flaw in the Email Address Encoder plugin developed by Till Krüss, specifically impacting versions ranging from the initial release through 1.0.22. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security flaws. The flaw manifests as improper neutralization of input during web page generation, creating an environment where malicious scripts can be injected and executed within the context of other users' browsers. The vulnerability is classified as stored XSS because the malicious payload is permanently stored on the server and then served to other users when they access affected pages, making it particularly insidious as it can affect multiple users over time without requiring repeated exploitation attempts.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the plugin's email address encoding functionality. When administrators or users input email addresses or related data into the plugin's interface, the system fails to properly sanitize or escape special characters that could be interpreted as HTML or JavaScript code. This allows attackers to inject malicious scripts that are then executed whenever the affected web page is rendered for other users. The vulnerability specifically occurs during the web page generation process where encoded email addresses are displayed, creating a persistent vector for malicious code execution. The flaw is particularly concerning because it leverages the plugin's legitimate functionality to deliver malicious payloads, making detection more difficult as the attacks appear to originate from trusted sources.
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, data exfiltration, and redirection to malicious sites. Attackers can exploit this vulnerability to steal user sessions, access sensitive information, modify content, or even escalate privileges within the affected web application. The stored nature of the vulnerability means that once exploited, the malicious payload remains active until the plugin is updated or the affected data is manually removed, creating a persistent threat vector. This vulnerability affects not only the plugin's direct functionality but also potentially compromises the entire WordPress installation, especially if users have administrative privileges. The risk is amplified because many WordPress users may not be aware of the plugin's vulnerability or may delay updating due to compatibility concerns.
Mitigation strategies for CVE-2023-48765 should prioritize immediate remediation through plugin updates to versions that address the XSS vulnerability. System administrators must ensure that all affected installations are updated to the latest version of the Email Address Encoder plugin, as the vendor has likely released patches to fix the input sanitization and output encoding issues. Organizations should implement comprehensive input validation measures and output encoding practices to prevent similar vulnerabilities in custom applications. The principle of least privilege should be enforced where possible, limiting the ability of untrusted users to inject content into the system. Additionally, web application firewalls and security monitoring systems should be configured to detect and block suspicious script injection attempts. Regular security audits and penetration testing should be conducted to identify potential XSS vulnerabilities in web applications, with particular attention to input fields, form submissions, and dynamic content generation processes. The vulnerability also highlights the importance of keeping all third-party plugins and themes updated, as outdated components often serve as primary attack vectors for sophisticated adversaries.