CVE-2012-6555 in LatestComment
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the LatestComment plugin 1.1 for Vanilla Forums allows remote attackers to inject arbitrary web script or HTML via the discussion title.
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Analysis
by VulDB Data Team • 05/23/2025
The CVE-2012-6555 vulnerability represents a critical cross-site scripting flaw within the LatestComment plugin version 1.1 for Vanilla Forums, a widely used open-source discussion platform. This vulnerability exists in the plugin's handling of user input within discussion titles, creating a pathway for malicious actors to execute arbitrary web scripts or HTML code within the context of other users' browsers. The issue stems from insufficient input validation and output encoding mechanisms that fail to properly sanitize user-provided data before it is rendered in the web interface.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious discussion title containing embedded script tags or HTML elements that are not properly escaped or filtered by the plugin's processing logic. When other users view the affected discussion page, their browsers execute the injected malicious code, potentially leading to session hijacking, credential theft, or redirection to malicious websites. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws where untrusted data is improperly incorporated into web pages without proper validation or encoding.
From an operational perspective, this vulnerability presents significant risks to Vanilla Forums installations that utilize the LatestComment plugin, particularly in environments where users have the ability to create or modify discussion topics. The impact extends beyond simple data corruption as it can enable attackers to escalate privileges, steal user sessions, or manipulate forum content in ways that compromise the integrity of the entire platform. The vulnerability is especially concerning because it operates at the user interface level, making it difficult to detect and remediate without comprehensive input validation measures.
The attack surface for this vulnerability is broad given the widespread adoption of Vanilla Forums and its plugins, with potential exploitation occurring in various deployment scenarios including corporate intranets, community forums, and educational platforms where user-generated content is prevalent. Security practitioners should consider this vulnerability in relation to ATT&CK technique T1566 which encompasses social engineering attacks through malicious content delivery, and T1059 which covers execution through scripting languages. Mitigation strategies should include immediate patching of the vulnerable plugin, implementation of strict input validation mechanisms, and comprehensive output encoding for all user-generated content to prevent similar issues in other components of the forum platform.