CVE-2013-5645 in webmail
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Roundcube webmail before 0.9.3 allow user-assisted remote attackers to inject arbitrary web script or HTML via the body of a message visited in (1) new or (2) draft mode, related to compose.inc; and (3) might allow remote authenticated users to inject arbitrary web script or HTML via an HTML signature, related to save_identity.inc.
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Analysis
by VulDB Data Team • 01/07/2022
The CVE-2013-5645 vulnerability represents a significant cross-site scripting flaw in Roundcube webmail software versions prior to 0.9.3, exposing users to persistent security risks through multiple attack vectors. This vulnerability operates within the core messaging functionality of the webmail client, specifically targeting the message composition and identity management components. The flaw allows remote attackers to execute malicious scripts in the context of a victim's browser session, potentially leading to unauthorized access to sensitive email data and user credentials. The vulnerability's impact extends beyond simple script injection, as it can enable attackers to establish persistent access to user accounts through session hijacking or credential theft mechanisms. The attack requires minimal user interaction, typically involving the victim visiting a malicious message in either new or draft mode, making it particularly dangerous in environments where users frequently interact with email content from untrusted sources.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within Roundcube's message handling components. The compose.inc file, which manages the composition interface, fails to properly sanitize user input when processing message bodies, allowing attackers to inject malicious HTML content that executes when the message is viewed. Similarly, the save_identity.inc component lacks proper sanitization of HTML signature fields, enabling authenticated users to inject malicious scripts through their email signatures. This dual vulnerability surface demonstrates a fundamental weakness in the application's security architecture, where multiple entry points for XSS attacks exist without adequate protection mechanisms. The vulnerability specifically relates to CWE-79, which defines cross-site scripting as a condition where untrusted data is sent to a web browser without proper validation, encoding, or filtering, making it a classic example of insecure data handling in web applications.
The operational impact of CVE-2013-5645 extends far beyond simple script execution, as it creates persistent security risks for organizations relying on Roundcube for email services. Attackers can exploit these vulnerabilities to steal session cookies, redirect users to malicious sites, or inject phishing content that appears legitimate within the email interface. The ability to inject scripts through message bodies means that even users who are not actively interacting with malicious content can be compromised simply by viewing infected messages, creating a broad attack surface. Additionally, the vulnerability's potential for authenticated exploitation through HTML signatures allows attackers who have gained access to legitimate user accounts to establish more persistent threats within the email system. This vulnerability can facilitate advanced persistent threats where attackers use the webmail interface as a foothold for further network infiltration, potentially accessing other systems within the organization that share the same authentication infrastructure. The attack vectors align with ATT&CK technique T1566, which covers social engineering through spearphishing and email-based attacks, demonstrating how this vulnerability can serve as a critical initial access point for broader security breaches.
Organizations affected by CVE-2013-5645 should immediately implement comprehensive mitigation strategies to address the identified XSS vulnerabilities. The primary recommendation involves upgrading to Roundcube version 0.9.3 or later, which includes proper input validation and output encoding mechanisms to prevent malicious script injection. Additionally, administrators should implement strict content filtering policies that sanitize all email content before delivery, particularly focusing on message bodies and signature fields. The implementation of Content Security Policy headers can provide an additional layer of protection by restricting script execution within the email interface. Network-level protections should include web application firewalls that can detect and block suspicious script injection attempts. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other webmail applications and ensure that proper input sanitization practices are maintained throughout the organization's email infrastructure. These measures align with industry best practices for preventing XSS attacks and maintaining secure webmail environments, as outlined in various security frameworks including NIST SP 800-171 and ISO 27001 standards.