CVE-2011-3854 in ZenLite
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the ZenLite theme before 4.4 for WordPress allows remote attackers to inject arbitrary web script or HTML via the s parameter.
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Analysis
by VulDB Data Team • 04/13/2017
The CVE-2011-3854 vulnerability represents a classic cross-site scripting flaw within the ZenLite theme for WordPress systems prior to version 4.4. This vulnerability resides in the theme's handling of user input through the s parameter, which is typically used for search functionality within WordPress installations. The flaw enables remote attackers to execute malicious scripts in the context of a victim's browser session, potentially leading to unauthorized actions performed on behalf of the user. The vulnerability specifically affects WordPress users who are running the ZenLite theme version 4.3 or earlier, making it a targeted issue for those particular installations.
The technical nature of this vulnerability aligns with CWE-79, which defines cross-site scripting as a weakness that allows attackers to inject client-side scripts into web applications. The s parameter in WordPress themes typically processes search queries and other user inputs without proper sanitization or output encoding, creating an opening for malicious code injection. When a user visits a page containing the vulnerable parameter, the malicious script gets executed in their browser context, potentially allowing attackers to steal session cookies, redirect users to malicious sites, or perform actions with the user's privileges. The vulnerability exists because the theme fails to implement proper input validation and output encoding mechanisms that would prevent such script injection attacks.
From an operational perspective, this vulnerability poses significant risks to WordPress installations using the affected ZenLite theme. Attackers can exploit this weakness by crafting malicious URLs containing script payloads in the s parameter, which when clicked by users, execute the injected code. This type of attack can lead to session hijacking, data theft, or further compromise of the affected WordPress site. The impact extends beyond individual user sessions to potentially compromise the entire website if attackers can leverage the vulnerability to gain administrative access or manipulate content. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring physical access to the target system, making it particularly dangerous for widely accessible WordPress installations.
Security mitigations for CVE-2011-3854 should focus on immediate remediation through theme updates to version 4.4 or later, which contain the necessary patches to address the input validation issues. Organizations should also implement comprehensive input sanitization measures and output encoding for all user-supplied data, particularly parameters used in search functionality. Network-based solutions such as web application firewalls can provide additional protection layers by filtering malicious requests before they reach the vulnerable application. The vulnerability demonstrates the importance of regular security updates and proper input validation practices, aligning with ATT&CK technique T1566 which covers social engineering through malicious content delivery. Additionally, implementing Content Security Policy headers can provide defense-in-depth measures to prevent execution of unauthorized scripts even if other protections fail. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other themes and plugins, as this type of flaw is common in WordPress ecosystems where proper security practices are not consistently implemented across all components.