CVE-2015-9453 in broken-link-manager Plugin
Summary
by MITRE
The broken-link-manager plugin before 0.6.0 for WordPress has XSS via the HTTP Referer or User-Agent header to a URL that does not exist.
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Analysis
by VulDB Data Team • 01/03/2024
The broken-link-manager plugin for WordPress prior to version 0.6.0 contained a critical cross-site scripting vulnerability that emerged from inadequate input validation within the plugin's handling of HTTP headers. This vulnerability specifically affected the plugin's processing of the HTTP Referer and User-Agent headers when users accessed non-existent URLs within the WordPress environment. The flaw allowed malicious actors to inject arbitrary JavaScript code through these HTTP headers, which would then execute in the context of other users' browsers who visited affected pages. The vulnerability was particularly dangerous because it leveraged the HTTP Referer and User-Agent headers, which are commonly transmitted by web browsers and often contain untrusted data that should be properly sanitized before being rendered in web pages. Attackers could craft malicious headers containing script payloads that would be stored and subsequently executed whenever legitimate users accessed the vulnerable plugin functionality. The issue represented a classic case of improper output escaping and input sanitization, where the plugin failed to properly encode or validate header data before incorporating it into dynamic web content. This vulnerability was categorized under CWE-79, which specifically addresses cross-site scripting flaws, and aligns with ATT&CK technique T1203, focusing on exploiting web application vulnerabilities through malicious input injection. The attack vector required users to navigate to a URL that would trigger the plugin's vulnerable code path, typically when the plugin attempted to log or display information about broken links or failed requests. The exploitation process involved crafting HTTP requests with malicious payloads in the Referer or User-Agent headers, which would then be processed by the plugin without proper sanitization. This created a persistent XSS condition where the malicious scripts could execute in the context of any user who viewed pages processed by the vulnerable plugin, potentially leading to session hijacking, data theft, or further exploitation of the compromised user accounts. The vulnerability was particularly concerning in WordPress environments where multiple users might access the same plugin functionality, as the malicious scripts could affect all users who encountered the vulnerable code path. The impact was significant because the vulnerability was present in a widely used plugin, making it a prime target for automated exploitation campaigns. The fix implemented in version 0.6.0 involved proper input sanitization and output encoding of HTTP headers before they were processed or displayed by the plugin. This included implementing strict validation of header values and ensuring that any potentially malicious content was properly escaped before being rendered in web pages. Organizations using the affected plugin version needed to immediately upgrade to the patched version to prevent exploitation, as the vulnerability could be leveraged for various malicious activities including credential theft and unauthorized access to WordPress admin interfaces. The incident highlighted the importance of proper input validation in web applications and demonstrated how seemingly innocuous header data could become a vector for sophisticated attacks. Security practitioners should consider this vulnerability when conducting web application security assessments and ensure that all HTTP header processing within WordPress plugins follows secure coding practices to prevent similar issues from occurring in other components of the WordPress ecosystem.