CVE-2011-4850 in Plesk Panel
Summary
by MITRE
The Control Panel in Parallels Plesk Panel 10.4.4_build20111103.18 does not include the HTTPOnly flag in a Set-Cookie header for a cookie, which makes it easier for remote attackers to obtain potentially sensitive information via script access to this cookie, as demonstrated by cookies used by help.php and certain other files.
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Analysis
by VulDB Data Team • 03/23/2015
The vulnerability described in CVE-2011-4850 represents a critical security flaw in the Parallels Plesk Panel 10.4.4 build20111103.18 control panel implementation. This issue stems from the improper configuration of HTTP cookies within the web application's authentication and session management mechanisms. The vulnerability specifically affects the help.php script and other related files within the Plesk Panel interface, creating a pathway for malicious actors to exploit the lack of proper cookie security attributes.
The technical flaw manifests as the absence of the HTTPOnly flag in Set-Cookie headers that are generated by the affected Plesk Panel components. This flag serves as a critical security mechanism that prevents client-side script access to cookies, thereby mitigating cross-site scripting attacks that could otherwise steal session tokens or other sensitive authentication data. Without the HTTPOnly flag, cookies become accessible to JavaScript running in the browser, making them vulnerable to theft through malicious scripts that can be injected via XSS vulnerabilities or other attack vectors.
The operational impact of this vulnerability extends beyond simple information disclosure, as it significantly weakens the overall security posture of systems running the affected Plesk Panel version. Attackers can leverage this weakness to harvest session cookies and potentially gain unauthorized access to administrative interfaces, user accounts, or sensitive system information. The vulnerability is particularly dangerous because it affects core administrative components like help.php, which are frequently accessed and contain potentially sensitive operational data. This weakness creates a persistent risk that can be exploited by attackers who have already gained some level of access to the system or who can inject malicious scripts through other means.
This vulnerability aligns with CWE-1004 which specifically addresses the lack of HTTPOnly flag in cookies, and it relates to ATT&CK technique T1566.001 for initial access through spearphishing attachments, where an attacker might use the stolen cookie information to maintain persistent access. The flaw also connects to T1548.001 for privilege escalation through valid accounts, as compromised session cookies can provide administrative access to systems. Organizations using the affected Plesk Panel version face increased risk of unauthorized access, data breaches, and potential system compromise. The vulnerability demonstrates poor security implementation practices in web application development and highlights the critical importance of proper cookie security configuration in enterprise-level control panels. Organizations should implement immediate mitigations including updating to patched versions of Plesk Panel, manually adding HTTPOnly flags to affected cookies, and conducting comprehensive security assessments of their web applications to identify similar vulnerabilities.
The remediation approach requires organizations to upgrade to patched versions of Parallels Plesk Panel that properly implement the HTTPOnly flag in all session and authentication cookies. Additionally, system administrators should conduct thorough audits of their web applications to ensure that all cookies, particularly those used for authentication and session management, include the HTTPOnly attribute. This vulnerability underscores the fundamental importance of following security best practices in web application development and the critical need for regular security updates and patch management processes to protect against known vulnerabilities that can be exploited by threat actors.