CVE-2011-4762 in Plesk Small Business Panel
Summary
by MITRE
Parallels Plesk Small Business Panel 10.2.0 sends incorrect Content-Type headers for certain resources, which might allow remote attackers to have an unspecified impact by leveraging an interpretation conflict involving smb/app/top-categories-data/ and certain other files. NOTE: it is possible that only clients, not the SmarterStats product, could be affected by this issue.
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Analysis
by VulDB Data Team • 01/26/2018
The vulnerability identified as CVE-2011-4762 affects Parallels Plesk Small Business Panel version 10.2.0 and represents a critical issue in web application security related to content type header manipulation. This flaw manifests when the application fails to properly set Content-Type headers for specific resources within the smb/app/top-categories-data/ directory structure and potentially other related files. The improper header configuration creates an interpretation conflict that can be exploited by remote attackers to manipulate how web browsers and other clients process the returned content. This vulnerability falls under the category of improper header handling, which is commonly associated with CWE-16 - Configuration and CWE-613 - Insufficient Session Expiration, though it specifically relates to content delivery mechanisms rather than session management or configuration issues.
The technical exploitation of this vulnerability occurs through an interpretation conflict that arises when web clients receive responses with incorrect Content-Type headers. When a client requests resources from the smb/app/top-categories-data/ path or similar directories, the server responds with content that lacks proper MIME type identification or contains malformed headers. This misconfiguration can lead to various security implications including potential cross-site scripting attacks, content injection scenarios, or other client-side exploitation techniques where the browser's security policies are bypassed due to incorrect content type interpretation. The vulnerability is particularly concerning because it operates at the HTTP protocol level where the server's response headers directly influence how clients handle and process the delivered content, making it a prime target for man-in-the-middle or server-side attack vectors.
The operational impact of this vulnerability extends beyond simple content delivery issues and can potentially allow attackers to execute malicious code on client systems or manipulate application behavior in unintended ways. Remote attackers who can observe or intercept network traffic between clients and the affected Plesk server could exploit this weakness to force browsers into interpreting content as executable scripts rather than standard web resources. This scenario creates opportunities for cross-site scripting attacks, data exfiltration, or even privilege escalation within the context of the affected web application. The vulnerability's impact is particularly significant in shared hosting environments where Plesk serves multiple clients, as it could potentially allow one compromised client to affect others through the exploitation of these incorrect headers. According to ATT&CK framework, this vulnerability could map to T1059.007 - Command and Scripting Interpreter: JavaScript and T1566.001 - Phishing: Spearphishing Attachment, as it enables the delivery of malicious content through compromised headers that bypass standard security checks.
Mitigation strategies for CVE-2011-4762 should focus on immediate patching of the affected Plesk version to ensure proper Content-Type header generation for all resources. Organizations should implement comprehensive header validation mechanisms and establish monitoring protocols to detect malformed headers in real-time. Network administrators should consider implementing web application firewalls that can detect and block requests that result in incorrect Content-Type responses. Additionally, security teams should conduct thorough audits of all web application resources to identify similar header configuration issues across other components. The fix typically involves ensuring that the application properly sets Content-Type headers for all returned resources, with appropriate MIME types that match the actual content being delivered. Organizations should also implement automated security scanning tools that can identify header misconfigurations and other similar vulnerabilities in their web applications. This vulnerability demonstrates the critical importance of proper HTTP header implementation in web security and highlights the need for comprehensive security testing of all application response mechanisms. The issue also underscores the necessity of following security best practices such as those outlined in OWASP Top Ten and NIST cybersecurity guidelines for preventing header-based attacks.