CVE-2008-5760 in MailServer
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in error413.php in Kerio MailServer before 6.6.2 allows remote attackers to inject arbitrary web script or HTML via the sent parameter. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/23/2019
The vulnerability identified as CVE-2008-5760 represents a critical cross-site scripting flaw located within the error413.php component of Kerio MailServer versions prior to 6.6.2. This issue manifests as a remote code execution vector that enables malicious actors to inject arbitrary web scripts or HTML content through the sent parameter, creating a significant security risk for affected systems. The vulnerability operates by failing to properly sanitize user input before rendering it within the web interface, thereby allowing attackers to execute malicious code within the context of other users' browsers.
The technical implementation of this XSS vulnerability stems from inadequate input validation and output encoding mechanisms within the Kerio MailServer's error handling subsystem. When the application encounters a 413 request entity too large error condition, it processes the sent parameter without proper sanitization, creating an opportunity for attackers to embed malicious scripts that will execute when other users view the affected page. This flaw aligns with CWE-79, which specifically addresses cross-site scripting vulnerabilities resulting from insufficient input validation and output encoding. The vulnerability demonstrates a classic example of how improper handling of user-supplied data can lead to persistent security weaknesses in web applications.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform a range of malicious activities including session hijacking, credential theft, and redirection to malicious sites. Attackers can leverage this vulnerability to steal user sessions, modify email content, or even escalate privileges within the mail server environment. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring local access to the system. According to ATT&CK framework, this vulnerability maps to T1059.007 for scripting and T1531 for credential access, as it provides a pathway for attackers to execute malicious code and obtain sensitive information.
Mitigation strategies for this vulnerability include immediate application of the vendor-provided patch version 6.6.2, which addresses the input sanitization issue in the error413.php file. Organizations should also implement additional defensive measures such as input validation at multiple layers, output encoding for all user-supplied data, and web application firewalls that can detect and block malicious script injection attempts. Network segmentation and access controls should be reviewed to limit exposure, while regular security assessments should be conducted to identify similar vulnerabilities in other components. The fix implemented by Kerio addresses the root cause by ensuring proper parameter validation and sanitization before any user input is processed or rendered within the web interface, thereby preventing the injection of malicious content through the sent parameter.