CVE-2011-4739 in Plesk Panel
Summary
by MITRE
The Control Panel in Parallels Plesk Panel 10.2.0 build 20110407.20 generates a password form field without disabling the autocomplete feature, which makes it easier for remote attackers to bypass authentication by leveraging an unattended workstation, as demonstrated by forms in smb/my-profile and certain other files.
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Analysis
by VulDB Data Team • 01/12/2018
The vulnerability identified as CVE-2011-4739 resides within the Parallels Plesk Panel version 10.2.0 build 20110407.20 and represents a significant security flaw in the control panel's authentication mechanism. This issue manifests specifically in the password form field implementation where the autocomplete feature remains enabled, creating an exploitable condition that undermines the security posture of the system. The vulnerability affects the administrative interface components, particularly the smb/my-profile section and related files, making it a critical concern for system administrators managing web hosting environments through this platform.
The technical flaw stems from improper implementation of HTML form attributes within the web interface components of Plesk Panel. When password fields are rendered without explicitly setting the autocomplete="off" attribute, browsers automatically cache these credentials in their local storage mechanisms. This behavior creates a persistent security risk because the cached credentials can be automatically populated into subsequent login forms, potentially allowing unauthorized access when users leave their workstations unattended. The vulnerability operates at the client-side interface level rather than the server-side authentication mechanism, making it particularly insidious as it exploits the trust relationship between the browser and the user's session.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables a class of attacks categorized under credential reuse and session hijacking techniques. An attacker with physical access to an unattended workstation can exploit this weakness by simply navigating to the cached login form, where their credentials will be automatically populated. This scenario aligns with attack patterns documented in the attack technique matrix under credential access and privilege escalation categories. The vulnerability particularly affects environments where multiple administrators share workstations or where security policies are not strictly enforced regarding workstation lock mechanisms.
The security implications of CVE-2011-4739 are exacerbated by its potential to enable broader compromise scenarios within hosting environments. When combined with other vulnerabilities or social engineering techniques, this weakness can serve as a foothold for more extensive attacks. The flaw demonstrates poor security hygiene in web application development practices, as it violates fundamental security principles outlined in the CWE (Common Weakness Enumeration) catalog under weakness category CWE-628 which addresses improper use of autocomplete. Organizations relying on Plesk Panel for hosting services face increased risk of unauthorized administrative access, potentially leading to complete system compromise, data breaches, and service disruption.
Mitigation strategies for this vulnerability require immediate implementation of security patches provided by Parallels, along with manual code modifications to ensure that all password fields within the control panel interface include the autocomplete="off" attribute. System administrators should also enforce strict workstation security policies including automatic screen locking, implement proper access control measures, and conduct regular security audits of web interface components. Additional protective measures include monitoring for unauthorized access attempts, implementing multi-factor authentication mechanisms, and ensuring that all users understand the importance of locking their workstations when stepping away from administrative tasks. The vulnerability serves as a reminder of the critical importance of secure coding practices and the need for regular security assessments of administrative interfaces to prevent exploitation through seemingly minor implementation flaws.