CVE-2014-3135 in vBulletin
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in vBulletin 5.1.1 Alpha 9 allow remote attackers to inject arbitrary web script or HTML via (1) the PATH_INFO to privatemessage/new/, (2) the folderid parameter to a private message in privatemessage/view, (3) a fragment indicator to /help, or (4) the view parameter to a topic, as demonstrated by a request to forum/anunturi-importante/rst-power/67030-rst-admin-restore.
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Analysis
by VulDB Data Team • 05/12/2026
The vulnerability identified as CVE-2014-3135 represents a critical cross-site scripting flaw affecting vBulletin 5.1.1 Alpha 9 forums, demonstrating the persistent security challenges inherent in web application frameworks that process user input without adequate sanitization. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically manifesting as stored XSS attacks that can persist across multiple user sessions and potentially compromise entire user bases through malicious script injection. The vulnerability affects multiple endpoints within the forum application, creating multiple attack vectors that collectively weaken the overall security posture of the platform.
The technical exploitation of this vulnerability occurs through four distinct parameter injection points that bypass input validation mechanisms within the vBulletin framework. The first vector involves injecting malicious content through PATH_INFO parameters when accessing the privatemessage/new/ endpoint, allowing attackers to execute scripts in the context of other users' browsers. The second vulnerability targets the folderid parameter in privatemessage/view, where improperly sanitized user input can be stored and subsequently executed when other users view private messages. The third attack vector utilizes fragment indicators in the /help endpoint, while the fourth exploits the view parameter in topic URLs, creating a chain of potential exploitation across different forum sections.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform session hijacking, steal user credentials, manipulate forum content, and potentially escalate privileges within the application. The vulnerability's persistence through stored XSS means that malicious scripts remain active even after the initial injection, continuously affecting users who access the compromised pages. Attackers could leverage this vulnerability to redirect users to malicious sites, harvest cookies, or inject additional malicious code that could compromise user accounts and potentially the entire forum infrastructure.
Security practitioners should implement comprehensive input sanitization measures and output encoding across all user-controllable parameters within the vBulletin application. The mitigation strategy must include strict validation of all PATH_INFO, parameter, and URL fragment inputs, with proper HTML encoding of all user-generated content before storage or display. Organizations should also consider implementing Content Security Policy headers to limit script execution and employ regular security scanning to identify similar vulnerabilities. This vulnerability aligns with ATT&CK technique T1566.001 for initial access through malicious links and T1059.001 for command and scripting interpreter execution, making it a significant concern for organizations relying on forum platforms for community interaction and information sharing.