CVE-2019-17207 in broken-link-checker
Summary
by MITRE
A reflected XSS vulnerability was found in includes/admin/table-printer.php in the broken-link-checker (aka Broken Link Checker) plugin 1.11.8 for WordPress. This allows unauthorized users to inject client-side JavaScript into an admin-only WordPress page via the wp-admin/tools.php?page=view-broken-links s_filter parameter in a search action.
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Analysis
by VulDB Data Team • 01/17/2024
The reflected cross-site scripting vulnerability identified as CVE-2019-17207 exists within the broken-link-checker WordPress plugin version 1.11.8, specifically in the includes/admin/table-printer.php file. This flaw represents a critical security weakness that enables attackers to execute malicious JavaScript code within the context of an administrator's browser session. The vulnerability manifests when user-supplied input from the s_filter parameter in the wp-admin/tools.php?page=view-broken-links URL path is not properly sanitized or validated before being rendered back to the user interface. The attack vector specifically targets administrative interfaces where privileged users access the broken link checker functionality, making this a particularly dangerous vulnerability due to the elevated privileges of the targeted users.
The technical implementation of this vulnerability stems from improper input validation and output encoding practices within the WordPress plugin's administrative interface. When an attacker crafts a malicious payload and submits it through the s_filter parameter, the plugin fails to adequately escape or sanitize the input before incorporating it into the HTML response. This allows the malicious JavaScript code to be executed when the page loads, effectively creating a reflected XSS attack vector. The vulnerability is classified as CWE-79 - Improper Neutralization of Input During Web Page Generation, which is a fundamental web application security weakness that occurs when user-controllable data is directly included in web page content without proper sanitization. The reflected nature of this attack means the malicious payload is immediately reflected back to the user without being stored on the server, making it particularly difficult to detect and prevent.
The operational impact of CVE-2019-17207 extends beyond simple script execution, as it provides attackers with the ability to perform actions with the privileges of authenticated administrators. Successful exploitation could allow attackers to steal session cookies, modify administrative settings, inject additional malicious content, or even redirect administrators to phishing sites. The vulnerability affects the administrative tools page where broken link checking functionality is accessible, making it a prime target for attackers seeking to gain unauthorized access to WordPress administrative interfaces. This poses significant risks to WordPress sites that rely on the broken-link-checker plugin, particularly those with multiple administrators or sites that handle sensitive data. The attack requires minimal prerequisites since it targets an existing administrative interface that would normally be accessible to legitimate users, making it an attractive target for exploitation.
Mitigation strategies for this vulnerability should include immediate patching of the broken-link-checker plugin to version 1.11.9 or later, which contains the necessary security fixes. Organizations should also implement input validation measures at the web application level to sanitize all user-supplied parameters before processing, particularly those used in administrative interfaces. Network-level protections such as web application firewalls can provide additional defense-in-depth measures to detect and block malicious payloads targeting this specific vulnerability. Security monitoring should be enhanced to detect unusual patterns in administrative interface access and parameter manipulation. The vulnerability aligns with ATT&CK technique T1566.002 - Phishing: Spearphishing Attachment, as attackers could potentially use this vulnerability to establish persistent access through malicious payloads delivered via compromised administrative sessions. Regular security audits of WordPress plugins and themes should be conducted to identify similar vulnerabilities, and privileged access should be restricted through proper access control measures including multi-factor authentication for administrative accounts.