CVE-2011-4855 in Plesk Panel
Summary
by MITRE
The Control Panel in Parallels Plesk Panel 10.4.4_build20111103.18 omits the Content-Type header s charset parameter for certain resources, which might allow remote attackers to have an unspecified impact by leveraging an interpretation conflict involving admin/customer-service-plan/list/reset-search/true/ and certain other files. NOTE: it is possible that only clients, not the Plesk product, could be affected by this issue.
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Analysis
by VulDB Data Team • 01/18/2018
The vulnerability identified as CVE-2011-4855 affects Parallels Plesk Panel version 10.4.4_build20111103.18 and relates to a critical security flaw in the Control Panel's handling of HTTP response headers. This issue specifically involves the omission of the charset parameter within the Content-Type header for certain resources, creating a potential avenue for remote attackers to exploit interpretation conflicts within the web application. The vulnerability manifests when accessing specific paths such as admin/customer-service-plan/list/reset-search/true/ and other related files within the Plesk interface. The omission of proper charset specification in HTTP headers represents a fundamental breakdown in web application security practices and can lead to various security implications including content injection attacks and cross-site scripting vulnerabilities.
The technical flaw stems from the application's failure to properly implement HTTP response header construction, specifically in how it handles character encoding declarations for web resources. According to CWE-1004, this vulnerability represents a weakness in security-related header handling that can lead to interpretation conflicts between client and server. When the Content-Type header lacks the charset parameter, browsers and other HTTP clients may default to different character encodings, creating inconsistencies that attackers can leverage to manipulate how content is interpreted. The vulnerability's impact is particularly concerning because it affects core administrative functionality within the Plesk Control Panel, potentially allowing unauthorized users to exploit the interpretation conflict to execute malicious actions or access sensitive information. This weakness aligns with ATT&CK technique T1190, which describes the use of content injection attacks to manipulate how applications process data.
The operational impact of this vulnerability extends beyond simple data integrity concerns to encompass potential unauthorized access and privilege escalation within the Plesk environment. Attackers could potentially exploit the charset interpretation conflict to inject malicious content or manipulate administrative interfaces, particularly when dealing with user inputs or data displays within the customer service plan management section. The vulnerability's scope suggests it could affect not only the administrative functions but also customer-facing features that rely on proper character encoding handling. Given that this issue involves the Plesk product's core web interface, the potential for exploitation increases significantly when considering that the application serves as a central management platform for hosting services. The fact that only clients, not the Plesk product itself, could be affected by this issue indicates a client-side interpretation vulnerability that may allow attackers to manipulate how web resources are rendered or processed by user agents.
Mitigation strategies for CVE-2011-4855 should focus on implementing proper HTTP header configuration within the Plesk Control Panel, ensuring that all Content-Type headers include appropriate charset specifications such as charset=utf-8. System administrators should consider implementing web application firewalls to monitor and block suspicious requests targeting the vulnerable paths, while also applying the latest security patches provided by Parallels. The vulnerability's classification under CWE-1004 emphasizes the need for comprehensive header validation and security configuration reviews. Organizations should also implement regular security assessments to identify similar header-related issues within their web applications. The remediation process must include thorough testing to ensure that charset parameters are consistently applied across all resources, particularly those accessed through the administrative interface. Additionally, implementing proper input validation and output encoding mechanisms will help prevent exploitation of similar interpretation conflicts that could arise from incomplete header specifications.