CVE-2014-5345 in Comment System
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in upgrade.php in the Disqus Comment System plugin before 2.76 for WordPress allows remote attackers to inject arbitrary web script or HTML via the step parameter.
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Analysis
by VulDB Data Team • 06/10/2025
The CVE-2014-5345 vulnerability represents a critical cross-site scripting flaw discovered in the Disqus Comment System plugin for WordPress, specifically affecting versions prior to 2.76. This vulnerability resides within the upgrade.php file and creates a significant security risk by allowing remote attackers to inject malicious web scripts or HTML content through the step parameter. The vulnerability stems from inadequate input validation and output sanitization mechanisms within the plugin's upgrade process, which is typically accessed during plugin updates or configuration changes. The flaw demonstrates a classic XSS vulnerability pattern where user-supplied input is directly incorporated into the web page response without proper encoding or validation, creating an attack surface that can be exploited by malicious actors to execute arbitrary code in the context of a victim's browser.
The technical implementation of this vulnerability allows attackers to manipulate the step parameter in the upgrade.php script, which is used to control the upgrade process flow. When the plugin processes this parameter without proper sanitization, it enables attackers to inject malicious payloads that can execute in the browser of any user who accesses the affected upgrade page. This type of vulnerability falls under CWE-79 - Improper Neutralization of Input During Web Page Generation, which is a fundamental weakness in web application security. The attack vector operates through the standard HTTP request mechanism where an attacker crafts a malicious URL containing the XSS payload in the step parameter, which when executed by a victim's browser, can lead to session hijacking, credential theft, or redirection to malicious sites.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with the capability to perform sophisticated attacks against WordPress installations using the Disqus plugin. When exploited, the vulnerability can enable attackers to steal administrative credentials, modify plugin configurations, or even take complete control of affected WordPress sites. The vulnerability affects all users who have the vulnerable Disqus plugin installed and are logged into WordPress administration panels, making it particularly dangerous in environments where multiple administrators have access. The attack requires minimal privileges since it operates at the user level through the web interface, and successful exploitation can lead to persistent compromise of the affected WordPress installations. This vulnerability directly maps to ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as attackers can craft malicious upgrade pages that appear legitimate to users, leveraging the trust users place in the WordPress administration interface.
Mitigation strategies for CVE-2014-5345 primarily focus on immediate plugin updates to version 2.76 or later, which contains the necessary patches to address the XSS vulnerability. System administrators should also implement input validation measures at the web application firewall level to filter out suspicious parameters in upgrade.php requests, particularly those containing script tags or unusual character sequences. Network-level protections can include implementing Content Security Policy headers that restrict script execution and prevent unauthorized code injection. Additionally, organizations should conduct regular security audits of installed WordPress plugins to identify and remediate similar vulnerabilities, as this represents a common pattern in plugin development where insufficient input sanitization leads to exploitable conditions. The vulnerability highlights the importance of maintaining up-to-date security practices and demonstrates how third-party plugins can introduce significant security risks to otherwise secure WordPress installations. Security monitoring should include detection of suspicious upgrade requests and parameter manipulation attempts, while user education about recognizing potentially malicious upgrade prompts can provide an additional layer of defense against exploitation attempts.