CVE-2017-18522 in eelv-newsletter Plugin
Summary
by MITRE
The eelv-newsletter plugin before 4.6.1 for WordPress has XSS in the address book.
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Analysis
by VulDB Data Team • 11/27/2023
The CVE-2017-18522 vulnerability represents a cross-site scripting flaw discovered in the eelv-newsletter plugin for WordPress, specifically affecting versions prior to 4.6.1. This security issue resides within the plugin's address book functionality, where user input is not properly sanitized or validated before being rendered in web pages. The vulnerability stems from inadequate output encoding practices that allow malicious actors to inject malicious scripts into the address book section of the plugin. The flaw operates by accepting user-supplied data through form fields or parameters that are subsequently displayed without proper HTML escaping or context-appropriate sanitization. Attackers can exploit this weakness by crafting malicious payloads that, when executed in a victim's browser, can perform unauthorized actions or steal sensitive information.
The technical implementation of this vulnerability follows the CWE-79 pattern for cross-site scripting, specifically categorized under reflected XSS due to the manner in which user input flows through the application to the final output. The vulnerability exists in the plugin's handling of address book data where input validation is insufficient to prevent script injection attempts. When users interact with the address book functionality, the plugin fails to properly escape special characters in user-provided content, creating an opening for malicious code execution. This flaw operates at the application layer and can be exploited through various vectors including direct user input, URL parameters, or even through crafted emails sent via the newsletter functionality. The attack chain typically involves an attacker crafting malicious input containing script tags or other malicious payloads that are then stored and subsequently executed when other users view the address book entries.
The operational impact of CVE-2017-18522 extends beyond simple script execution, as it can lead to complete session hijacking, credential theft, or redirection to malicious sites. When exploited, this vulnerability allows attackers to execute arbitrary JavaScript code within the context of a victim's browser session, potentially compromising user accounts with elevated privileges. The attack surface includes not only the immediate address book functionality but also any other areas of the plugin that may share similar input handling patterns. This vulnerability can be particularly dangerous in multi-user environments where administrators might be tricked into viewing malicious entries, potentially leading to privilege escalation or data exfiltration. The impact is amplified by the fact that WordPress plugins often have access to sensitive user data and administrative functions, making the exploitation of such vulnerabilities particularly concerning for website owners and users.
Mitigation strategies for CVE-2017-18522 primarily focus on immediate plugin updates to version 4.6.1 or later, which contain the necessary security patches to address the XSS vulnerability. System administrators should also implement additional security measures including input validation, output encoding, and regular security audits of installed plugins. The implementation of Content Security Policy headers can provide additional protection against script execution even if the vulnerability is not fully patched. Organizations should also consider implementing web application firewalls to detect and block malicious payloads attempting to exploit this vulnerability. Regular monitoring of plugin repositories and security advisories is essential to identify similar vulnerabilities in other installed components. According to ATT&CK framework, this vulnerability maps to T1059.007 for script injection techniques and T1566 for social engineering attacks that might leverage this flaw to compromise user sessions. The vulnerability demonstrates the importance of proper input sanitization and output encoding practices as outlined in OWASP Top Ten security principles, emphasizing the need for defense-in-depth strategies that protect against multiple attack vectors.