CVE-2013-6906 in Garoon
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in a mail component in Cybozu Garoon before 3.7.0, when Internet Explorer 6 through 8 is used, allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/02/2019
The vulnerability identified as CVE-2013-6906 represents a cross-site scripting flaw within the mail component of Cybozu Garoon software versions prior to 3.7.0. This security weakness specifically manifests when the application is accessed through Internet Explorer versions 6 through 8, creating a targeted attack surface that exploits the browser-specific rendering behaviors and scripting capabilities of these older Microsoft Internet Explorer versions. The vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is a fundamental web application security weakness that enables attackers to inject malicious scripts into web pages viewed by other users. The affected environment creates a particularly dangerous scenario given that Internet Explorer 6 through 8 were widely deployed in enterprise environments during the period when this vulnerability existed, making the potential impact substantial.
The technical implementation of this XSS vulnerability stems from inadequate input validation and output encoding within the mail component's handling of user-supplied data. When users interact with the mail functionality in affected versions of Cybozu Garoon, the application fails to properly sanitize or encode data that is subsequently rendered in web pages. This allows malicious actors to craft specially formatted input that, when processed by the vulnerable application, gets executed within the browser context of legitimate users. The unspecified vectors suggest that the vulnerability could be triggered through various data entry points within the mail component, including but not limited to email subject lines, message bodies, or recipient fields. The attack requires no special privileges and can be executed remotely, making it particularly dangerous for organizations that rely on the Garoon platform for email and collaboration services.
The operational impact of this vulnerability extends beyond simple script execution, as it creates opportunities for attackers to perform session hijacking, steal user credentials, redirect users to malicious websites, or perform actions on behalf of authenticated users. In enterprise environments where Cybozu Garoon serves as a primary collaboration platform, this vulnerability could enable attackers to access sensitive corporate communications, compromise user accounts, and potentially escalate privileges within the organization's network. The specific targeting of Internet Explorer 6 through 8 versions is significant because these browsers had known security limitations and were often used in legacy enterprise systems where upgrading was not immediately feasible. This creates a dangerous combination where organizations with older browser deployments face increased exposure to exploitation while potentially lacking the modern security features found in newer browser versions.
Organizations should implement immediate mitigations including updating to Cybozu Garoon version 3.7.0 or later, which contains the necessary patches to address the XSS vulnerability. Additionally, administrators should consider implementing content security policies, input validation measures, and output encoding controls to reduce the attack surface. The vulnerability demonstrates the importance of maintaining up-to-date software versions and the risks associated with supporting legacy browser environments. From an ATT&CK framework perspective, this vulnerability maps to T1566 (Phishing) and T1059 (Command and Scripting Interpreter) techniques, as attackers could use the XSS flaw to deliver malicious payloads and execute commands within user browsers. Security teams should also consider implementing web application firewalls and monitoring for suspicious script injection attempts in their email systems to detect and prevent exploitation attempts.