CVE-2012-6121 in Roundcube
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Roundcube Webmail before 0.8.5 allows remote attackers to inject arbitrary web script or HTML via a (1) data:text or (2) vbscript link.
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Analysis
by VulDB Data Team • 12/29/2021
The CVE-2012-6121 vulnerability represents a critical cross-site scripting flaw discovered in Roundcube Webmail versions prior to 0.8.5, fundamentally compromising user security through malicious script injection. This vulnerability specifically targets the application's handling of data URIs and vbscript protocols, creating pathways for remote attackers to execute arbitrary web scripts or HTML code within the context of authenticated user sessions. The flaw arises from insufficient input validation and sanitization mechanisms within the webmail application's processing of user-supplied data, particularly when handling specially crafted links that leverage the data:text and vbscript schemes.
The technical implementation of this vulnerability exploits the webmail application's failure to properly filter or escape user-controllable input parameters that are subsequently rendered in web pages without adequate sanitization. When a user encounters a maliciously crafted email message containing a data:text URI or vbscript link, the application processes these elements without proper validation, allowing the embedded scripts to execute within the user's browser context. This creates a persistent threat vector where attackers can manipulate the webmail interface to perform actions such as stealing session cookies, redirecting users to malicious sites, or executing unauthorized commands on behalf of the victim.
The operational impact of this vulnerability extends beyond simple script execution, as it enables sophisticated attack scenarios that can compromise entire user sessions and potentially lead to broader system infiltration. Attackers can leverage this flaw to establish persistent access to user accounts, harvest sensitive information, or use the compromised sessions as stepping stones for further attacks within the network. The vulnerability's remote nature means that attackers do not require physical access to the system or direct network access to exploit the flaw, making it particularly dangerous in enterprise environments where webmail systems serve as primary communication channels.
Security professionals should note that this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in software applications, and maps to ATT&CK technique T1059.007 for script injection attacks. Organizations should implement immediate mitigations including updating to Roundcube Webmail version 0.8.5 or later, which contains the necessary patches to address the XSS vulnerability. Additional defensive measures should include implementing robust input validation mechanisms, deploying web application firewalls, and conducting regular security assessments to identify similar vulnerabilities in other web applications. The incident underscores the critical importance of maintaining current software versions and implementing comprehensive security controls to protect against persistent threats that exploit input validation weaknesses in web-based applications.