CVE-2015-8864 in RoundCube
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Roundcube Webmail before 1.0.9 and 1.1.x before 1.1.5 allows remote attackers to inject arbitrary web script or HTML via a crafted SVG, a different vulnerability than CVE-2016-4068.
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Analysis
by VulDB Data Team • 11/29/2022
The CVE-2015-8864 vulnerability represents a critical cross-site scripting flaw discovered in Roundcube Webmail, a widely deployed web-based email client application. This vulnerability specifically affects versions prior to 1.0.9 in the 1.0.x series and versions prior to 1.1.5 in the 1.1.x series, creating a significant security risk for organizations relying on this email platform. The flaw stems from insufficient input validation and sanitization mechanisms within the application's handling of SVG (Scalable Vector Graphics) content, which is commonly used for rich media integration in web applications. Unlike other similar vulnerabilities such as CVE-2016-4068, this particular flaw operates through a distinct attack vector that specifically targets SVG file processing, making it a unique threat within the Roundcube ecosystem.
The technical implementation of this vulnerability occurs when the webmail application processes SVG files that contain malicious script code embedded within their structure. Attackers can craft specially designed SVG files that appear legitimate but contain embedded JavaScript or HTML content that executes in the context of other users' browsers when the malicious SVG is viewed within the Roundcube interface. This occurs because the application fails to properly sanitize SVG content before rendering it, allowing attackers to inject arbitrary web scripts that can perform actions such as stealing session cookies, redirecting users to malicious sites, or executing unauthorized commands on behalf of the victim. The vulnerability operates at the application layer and leverages the trust relationship between the webmail client and its users, making it particularly dangerous in enterprise environments where multiple users interact with the same system.
The operational impact of CVE-2015-8864 extends beyond simple data theft, as it provides attackers with a powerful vector for conducting sophisticated social engineering campaigns and persistent attacks against organizational email systems. When exploited successfully, this vulnerability enables attackers to compromise user sessions and potentially gain access to sensitive email communications, personal information, and business-critical data stored within the Roundcube webmail environment. The attack surface is particularly concerning given that email systems serve as primary communication channels for most organizations, making them attractive targets for cybercriminals seeking to establish persistent access or conduct targeted attacks. The vulnerability's classification aligns with CWE-79, which specifically addresses Cross-Site Scripting flaws in web applications, and represents a significant deviation from secure coding practices that should prevent untrusted input from being rendered without proper sanitization.
Organizations affected by this vulnerability should prioritize immediate remediation through the application of available security patches and updates to Roundcube Webmail versions 1.0.9 and 1.1.5 or later, as these releases contain the necessary fixes to address the SVG sanitization issues. System administrators should implement comprehensive security monitoring to detect potential exploitation attempts and establish network-level controls to prevent the delivery of malicious SVG content to users. Additional mitigations include implementing strict content filtering policies for email attachments, deploying web application firewalls to detect and block malicious SVG content, and conducting regular security assessments of webmail environments to identify similar vulnerabilities. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for script-based attacks, highlighting the importance of input validation and output encoding as primary defensive measures against such threats. Organizations should also consider implementing security awareness training for users to recognize potential phishing attempts that may leverage this vulnerability, as user education remains a critical component of comprehensive cybersecurity defense strategies.