CVE-2011-4731 in Plesk Panel
Summary
by MITRE
The Server Administration Panel in Parallels Plesk Panel 10.2.0_build1011110331.18 includes an RFC 1918 IP address within a web page, which allows remote attackers to obtain potentially sensitive information by reading this page, as demonstrated by admin/home/admin and certain other files.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/13/2018
The vulnerability described in CVE-2011-4731 represents a significant information disclosure issue within Parallels Plesk Panel version 10.2.0_build101110331.18. This flaw manifests in the Server Administration Panel where RFC 1918 IP addresses are inadvertently exposed within web page content, creating a potential attack vector for remote threat actors. The specific files mentioned include admin/home/admin and other related administrative components that contain this sensitive information disclosure. RFC 1918 addresses refer to private IP address ranges that should typically remain hidden from external exposure, making their presence in publicly accessible web pages particularly concerning for security practitioners. The vulnerability falls under the category of information disclosure as defined by CWE-200, which encompasses weaknesses that allow unauthorized parties to gain access to information that should remain confidential. This type of exposure can provide attackers with valuable network topology information that may aid in subsequent reconnaissance activities.
The technical implementation of this vulnerability stems from improper input validation and output sanitization within the administrative web interface. When administrators access certain control panel pages, the system renders content that includes private IP addresses from the RFC 1918 range, which are typically reserved for internal network use. These addresses should never be exposed to external users or systems, as they reveal internal network structure and potentially sensitive infrastructure details. The vulnerability is particularly concerning because it affects core administrative functionality, meaning that any remote attacker who can access the web interface could extract this information simply by reading the rendered HTML pages. This exposure creates a foundation for further attacks, as attackers can use the discovered IP addresses to map internal network topology and identify potential targets for more sophisticated attacks.
The operational impact of this vulnerability extends beyond simple information disclosure, creating potential risks for organizations using Parallels Plesk Panel. The exposure of RFC 1918 addresses can facilitate network mapping and reconnaissance activities that would otherwise be difficult to perform from external positions. Attackers can leverage this information to understand internal network architecture, identify potential internal services, and plan more targeted attacks against specific network segments. This vulnerability particularly affects organizations that rely on Plesk for hosting management, as it provides a direct avenue for attackers to gather intelligence about internal network configurations. The risk is compounded by the fact that the vulnerability exists in administrative components, which typically have elevated privileges and access to sensitive system information. According to ATT&CK framework, this represents a technique for reconnaissance and information gathering, specifically related to network service scanning and discovery activities.
Organizations affected by this vulnerability should implement immediate mitigations to prevent unauthorized access to administrative interfaces and ensure proper input sanitization. The primary recommendation involves restricting access to administrative pages through proper authentication mechanisms and network segmentation. Additionally, administrators should verify that all web server configurations properly sanitize output to prevent the accidental disclosure of internal IP addresses. Security teams should implement monitoring for unusual access patterns to administrative interfaces and consider implementing web application firewalls to detect and prevent exploitation attempts. The vulnerability demonstrates the importance of proper input validation and output sanitization practices as outlined in OWASP Top 10 and other security standards. Organizations should also conduct regular security assessments of their administrative interfaces to identify similar information disclosure vulnerabilities that could compromise network security posture. The remediation process should include updating to patched versions of Parallels Plesk Panel and implementing comprehensive access controls to limit exposure of sensitive administrative functions to authorized personnel only.