CVE-2012-4071 in Com Rsgallery2
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the comments module in the RSGallery2 (com_rsgallery2) component before 2.3.0 for Joomla! 1.5.x, and before 3.2.0 for Joomla! 2.5.x, allows remote attackers to inject arbitrary web script or HTML via crafted BBCode markup in a comment.
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Analysis
by VulDB Data Team • 01/10/2018
The CVE-2012-4071 vulnerability represents a critical cross-site scripting flaw within the RSGallery2 component for Joomla 1.5.x and 3.2.0 for Joomla
websites. The flaw specifically manifests when the component processes user-generated content through BBCode markup, a simplified markup language commonly used for formatting text in forums and content management systems. Attackers can exploit this weakness by crafting malicious BBCode sequences that, when processed by the vulnerable component, execute unintended JavaScript code within the context of other users' browsers. This vulnerability directly maps to CWE-79, which categorizes cross-site scripting as a code injection flaw that allows attackers to execute malicious scripts in the victim's browser context. The security implications extend beyond simple script execution, as this vulnerability can be leveraged to perform session hijacking, deface websites, steal sensitive user information, or redirect users to malicious domains. The attack vector is particularly concerning because it requires minimal privileges to exploit, as users only need to submit comments containing malicious BBCode markup to compromise other users who view those comments.
The technical exploitation of this vulnerability occurs through the improper sanitization of user input within the comments processing pipeline of the RSGallery2 component. When users submit comments containing crafted BBCode elements, the vulnerable code fails to adequately validate or escape special characters that could be interpreted as HTML or JavaScript commands. This processing flaw allows attackers to inject malicious payloads directly into the comment display mechanism, where the malicious code executes in the browser context of other visitors. The vulnerability is particularly dangerous in environments where users can submit comments without proper moderation or filtering, as it enables attackers to create persistent XSS payloads that affect all users who view the compromised comments. The exploitation process typically involves embedding JavaScript code within BBCode tags or using HTML entities that bypass standard input validation mechanisms. The attack can be further amplified by leveraging the fact that many Joomla! installations do not implement comprehensive output encoding for user-generated content, creating an environment where malicious code can persist and propagate across multiple user sessions.
The operational impact of CVE-2012-4071 extends far beyond simple data theft or defacement, as it provides attackers with persistent access to compromised websites and their users. Once exploited, the vulnerability enables attackers to manipulate the content displayed to users, potentially redirecting them to phishing sites, stealing session cookies, or modifying gallery content to spread malware. The vulnerability affects the integrity and confidentiality of user data, as users may unknowingly execute malicious code when viewing gallery comments, leading to potential data breaches and unauthorized access to sensitive information. Organizations using vulnerable versions of RSGallery2 face significant reputational damage, as compromised websites can be used to distribute malware, conduct phishing attacks, or serve as command and control centers for larger cyber operations. The attack surface is particularly broad since RSGallery2 was widely adopted across numerous Joomla! installations, meaning that a single vulnerable component could compromise thousands of websites. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1566 (Phishing) and T1059 (Command and Scripting Interpreter) where attackers can leverage the XSS flaw to establish persistent access and execute malicious payloads. The vulnerability also enables lateral movement within compromised networks, as attackers can use stolen session tokens to gain access to administrative functions or other sensitive areas of the website.
Organizations affected by CVE-2012-4071 should implement immediate mitigation strategies to protect their Joomla 1.5.x and 3.2.0 for Joomla
installation. The vulnerability also highlights the importance of maintaining current security patches for all third-party extensions, as many organizations fail to update their components regularly, leaving them exposed to known exploits. Network monitoring should be enhanced to detect suspicious traffic patterns that might indicate exploitation attempts, and user access controls should be reviewed to ensure that only authorized individuals can submit comments or modify content within the gallery system.