CVE-2012-2571 in WinWebMail Server
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in WinWebMail Server 3.8.1.6 allow remote attackers to inject arbitrary web script or HTML via an e-mail message body with (1) a SCRIPT element, (2) a crafted Cascading Style Sheets (CSS) expression property, (3) a CSS expression property in the STYLE attribute of an arbitrary element, (4) a crafted SRC attribute of an IFRAME element, or (5) UTF-7 text in an HTTP-EQUIV="CONTENT-TYPE" META element.
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Analysis
by VulDB Data Team • 01/27/2026
The CVE-2012-2571 vulnerability represents a critical cross-site scripting flaw in WinWebMail Server version 3.8.1.6 that exposes users to significant web application security risks. This vulnerability stems from insufficient input validation and output encoding mechanisms within the email server's message processing pipeline, allowing malicious actors to inject malicious script code directly into email content that gets rendered in web browsers. The vulnerability specifically affects how the server handles various HTML elements and attributes during email message display, creating multiple attack vectors that can be exploited through crafted email messages. The affected server version demonstrates a fundamental lack of proper sanitization for user-supplied content, particularly in email bodies that contain rich text formatting capabilities.
The technical exploitation of this vulnerability occurs through five distinct methods that leverage different HTML and CSS parsing behaviors in web browsers. The first vector involves direct injection of SCRIPT elements into email message bodies, which bypasses basic security filters by appearing as legitimate email content. The second and third vectors utilize CSS expression properties, specifically targeting the CSS expression property and STYLE attributes that browsers interpret as executable code. The fourth vector exploits IFRAME elements with crafted SRC attributes, enabling attackers to load malicious content from remote servers. The fifth and most sophisticated vector leverages UTF-7 encoding in HTTP-EQUIV="CONTENT-TYPE" META elements, which can be used to bypass traditional filtering mechanisms by encoding malicious payloads in a manner that appears legitimate to the server's content processing logic. This multi-vector approach demonstrates the complexity of modern web application security challenges and the importance of comprehensive input validation.
The operational impact of CVE-2012-2571 extends beyond simple script injection, potentially enabling attackers to perform session hijacking, redirect users to malicious websites, steal sensitive information, or execute arbitrary commands on affected systems. When users access compromised email messages through web-based interfaces, the injected scripts can exploit browser vulnerabilities, steal cookies, or redirect users to phishing sites that appear legitimate. The vulnerability particularly affects organizations using WinWebMail Server in environments where email security is paramount, as it can be leveraged to compromise user sessions and potentially escalate privileges within the email infrastructure. The attack surface is broad since any user who accesses email content through the vulnerable web interface becomes a potential target, making this a significant risk for organizations that rely on web-based email access.
Organizations affected by this vulnerability should implement immediate mitigations including updating to a patched version of WinWebMail Server, implementing comprehensive input validation at multiple levels, and deploying web application firewalls to filter malicious content. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and maps to ATT&CK technique T1566 for initial access through spearphishing with malicious attachments. Additional security measures should include disabling unnecessary HTML rendering capabilities in email clients, implementing content security policies, and conducting regular security assessments of web applications. The vulnerability also highlights the importance of proper encoding and sanitization of user-supplied content, particularly in web-based email systems where users can submit rich text content that gets rendered in browsers. Organizations should also consider implementing email security gateways and monitoring for suspicious email patterns that might indicate exploitation attempts.