CVE-2015-5381 in RoundCube
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in program/include/rcmail.php in Roundcube Webmail 1.1.x before 1.1.2 allows remote attackers to inject arbitrary web script or HTML via the _mbox parameter to the default URI.
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Analysis
by VulDB Data Team • 12/07/2022
The CVE-2015-5381 vulnerability represents a critical cross-site scripting flaw in Roundcube Webmail version 1.1.x prior to 1.1.2, specifically within the program/include/rcmail.php component. This vulnerability exposes webmail applications to remote code execution risks through improper input validation mechanisms. The flaw manifests when the application fails to adequately sanitize user-supplied input passed through the _mbox parameter in the default URI, creating an avenue for malicious actors to inject arbitrary web scripts or HTML content directly into the application's response stream.
The technical implementation of this vulnerability stems from insufficient parameter validation and output encoding practices within the Roundcube webmail application. When the application processes the _mbox parameter without proper sanitization, it allows attackers to inject malicious payloads that execute in the context of other users' browsers. This type of vulnerability falls under CWE-79, which specifically addresses Cross-Site Scripting conditions where applications fail to properly encode or validate user-controllable data before incorporating it into dynamically generated web pages. The vulnerability operates at the application layer and requires no special privileges to exploit, making it particularly dangerous in environments where multiple users share the same webmail infrastructure.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, steal user credentials, redirect victims to malicious sites, or execute arbitrary commands within the context of the victim's browser session. Given that Roundcube Webmail serves as a critical communication platform for many organizations, successful exploitation could compromise sensitive email communications and potentially lead to broader network infiltration. The vulnerability affects all versions of Roundcube Webmail 1.1.x before 1.1.2, representing a significant security gap that could be exploited by attackers with minimal technical expertise, as the attack vector involves simply manipulating URL parameters.
Mitigation strategies for CVE-2015-5381 primarily focus on immediate patch deployment and input validation improvements. Organizations should prioritize upgrading to Roundcube Webmail version 1.1.2 or later, which includes proper parameter sanitization and output encoding mechanisms. Additionally, implementing proper input validation at the application level, including the use of Content Security Policy headers, can provide defense-in-depth measures against similar vulnerabilities. From an ATT&CK framework perspective, this vulnerability maps to T1059.008 for the execution of malicious scripts and T1566 for the initial compromise through web application attacks. Network-level protections such as web application firewalls and regular security scanning can help detect and prevent exploitation attempts, while user education regarding suspicious email attachments and links remains crucial for overall security posture.