CVE-2017-18565 in Updater Plugin
Summary
by MITRE
The updater plugin before 1.35 for WordPress has multiple XSS issues.
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Analysis
by VulDB Data Team • 11/28/2023
The CVE-2017-18565 vulnerability affects the updater plugin for WordPress versions prior to 1.35, exposing multiple cross-site scripting flaws that represent significant security risks for WordPress installations. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically targeting the plugin's handling of user input in the update process. The flaw exists in how the plugin processes and displays data returned from update checks, creating opportunities for malicious actors to inject arbitrary JavaScript code into the WordPress administration interface. These XSS vulnerabilities are particularly dangerous because they can be exploited by attackers to execute malicious scripts in the context of the victim's browser, potentially leading to unauthorized actions within the WordPress admin environment.
The technical implementation of this vulnerability stems from insufficient input sanitization and output escaping within the updater plugin's codebase. When WordPress performs automatic update checks or displays update information, the plugin fails to properly sanitize user-supplied data that may be included in update responses from external servers. Attackers can craft malicious update responses containing script tags or other malicious payloads that get executed when administrators view update notifications or plugin information pages. The vulnerability affects both reflected and stored XSS scenarios, making it particularly versatile in attack vectors. The flaw is directly related to the plugin's improper handling of update metadata, where plugin names, descriptions, or version information may contain malicious code that gets rendered without proper HTML escaping mechanisms.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to escalate privileges within the WordPress environment. An authenticated attacker with access to the WordPress admin panel could leverage these XSS flaws to steal session cookies, modify plugin configurations, or even inject backdoors into the WordPress installation. The vulnerability is particularly concerning because it affects the core update mechanism that WordPress administrators rely on for maintaining security. When administrators view update notifications, they are essentially providing a trusted execution environment where malicious scripts can run with the privileges of the logged-in user. This creates potential for privilege escalation attacks where attackers could gain administrative access to WordPress sites, leading to complete compromise of the web application and potentially the underlying server infrastructure.
Mitigation strategies for CVE-2017-18565 should prioritize immediate patching of the updater plugin to version 1.35 or later, which includes proper input validation and output escaping mechanisms. Organizations should also implement content security policies that restrict script execution within the WordPress admin interface, limiting the impact of any remaining vulnerabilities. Regular security audits of WordPress plugins and themes are essential to identify similar vulnerabilities that may exist in other third-party components. The ATT&CK framework categorizes this type of vulnerability under T1211 - Exploitation for Privilege Escalation, highlighting the potential for attackers to use such flaws to gain elevated system access. Additionally, implementing web application firewalls and monitoring for suspicious update-related requests can provide additional layers of protection. Security teams should also consider implementing strict plugin management policies that require thorough security reviews before deploying any third-party plugins to production environments, particularly those that interact with update mechanisms or external data sources.