CVE-2012-4668 in Roundcube
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Roundcube Webmail 0.8.1 and earlier allows remote attackers to inject arbitrary web script or HTML via the signature in an email.
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Analysis
by VulDB Data Team • 04/07/2025
The CVE-2012-4668 vulnerability represents a critical cross-site scripting flaw discovered in Roundcube Webmail versions 0.8.1 and earlier, presenting a significant security risk to organizations relying on this email client platform. This vulnerability specifically targets the email signature handling functionality, creating an attack vector that enables remote threat actors to execute malicious code within the context of authenticated user sessions. The flaw exists in the web application's input sanitization mechanisms, where user-provided signature data fails to undergo proper validation and encoding before being rendered in web pages. This weakness allows attackers to inject malicious scripts that can be executed when other users view emails containing the crafted signatures, potentially compromising user sessions and accessing sensitive data.
The technical exploitation of this vulnerability occurs through the manipulation of email signature fields within the Roundcube interface, where input validation is insufficient to prevent the injection of malicious HTML or JavaScript code. When a victim views an email containing an attacker-controlled signature, the malicious code executes within the victim's browser context, potentially leading to session hijacking, credential theft, or data exfiltration. The vulnerability is classified as a persistent XSS attack since the malicious payload remains embedded in the email signature and can affect multiple users over time. This type of vulnerability falls under CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly sanitize user inputs before incorporating them into web content. The attack pattern aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, where malicious email content serves as the initial infection vector.
The operational impact of CVE-2012-4668 extends beyond simple script execution, as it can enable sophisticated attack chains where threat actors leverage the XSS vulnerability to establish persistent access to user accounts. An attacker could craft signatures containing malicious code that redirects users to phishing sites, steals session cookies, or performs actions on behalf of authenticated users. This vulnerability particularly affects organizations using Roundcube Webmail as their primary email solution, potentially compromising thousands of user accounts if not addressed promptly. The risk is amplified by the fact that email signatures are commonly viewed by multiple users within an organization, creating a potential for widespread compromise. Organizations may face regulatory compliance issues, data breaches, and reputational damage if this vulnerability is exploited successfully. The vulnerability's impact is further compounded by the fact that it requires minimal user interaction beyond viewing the affected email, making it particularly dangerous in enterprise environments where email communication is frequent and trusted.
Mitigation strategies for CVE-2012-4668 should prioritize immediate patching of Roundcube Webmail installations to versions 0.8.2 or later, where the XSS vulnerability has been addressed through proper input sanitization and output encoding. Organizations should implement comprehensive input validation measures that encode special characters in email signature fields, preventing the execution of embedded scripts. Web application firewalls can provide additional protection by monitoring for suspicious patterns in user inputs and blocking malicious payloads before they can be processed. Security teams should conduct regular vulnerability assessments and penetration testing to identify similar input validation weaknesses in other web applications. The implementation of content security policies can further reduce the impact of successful XSS attempts by restricting the execution of inline scripts and external resource loading. Additionally, user education about the risks of viewing suspicious email content and the importance of keeping software updated remains crucial in defending against exploitation of this vulnerability. Organizations should also consider implementing email filtering solutions that can detect and quarantine emails containing potentially malicious signatures, providing an additional layer of defense against this specific attack vector.