CVE-2018-20914 in cPanel
Summary
by MITRE
In cPanel before 70.0.23, OpenID providers can inject arbitrary data into cPanel session files (SEC-368).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2018-20914 affects cPanel versions prior to 70.0.23 and represents a significant security flaw in the session management mechanism of the web hosting control panel. This issue falls under the category of session manipulation and data injection attacks that can compromise the integrity of user sessions within the cPanel environment. The vulnerability specifically relates to how cPanel handles session data when integrating with OpenID providers, creating a pathway for malicious actors to inject arbitrary data into session files that should remain protected and controlled by the system.
The technical flaw stems from insufficient input validation and sanitization within cPanel's session handling code when processing data from OpenID authentication providers. When users authenticate through OpenID providers, the system should properly validate and sanitize all incoming session data to prevent unauthorized modifications. However, in affected versions, the system fails to adequately filter or validate the data received from these external authentication sources, allowing attackers to inject malicious or unexpected data into the session files. This injection can occur during the authentication process when cPanel processes the OpenID response and stores relevant information in session storage.
The operational impact of this vulnerability is substantial as it can lead to session hijacking, privilege escalation, and potential unauthorized access to user accounts within the cPanel environment. Attackers who successfully exploit this vulnerability can manipulate session data to gain elevated privileges, impersonate legitimate users, or execute unauthorized actions within the cPanel interface. The security implications extend beyond individual user accounts as compromised sessions could potentially allow attackers to access multiple accounts or perform administrative functions within the hosting environment. This type of vulnerability is particularly dangerous in shared hosting environments where multiple users may be managing different accounts on the same server.
This vulnerability aligns with CWE-20, which describes "Improper Input Validation," and represents a specific instance of insecure session management where external data is not properly sanitized before being stored in session files. The issue also relates to ATT&CK technique T1548.002, which covers "Abuse Elevation Control Mechanism: Bypass UAC," as the session manipulation could potentially bypass user authentication mechanisms and elevate privileges. Organizations using cPanel versions prior to 70.0.23 should immediately implement the available security patch from cPanel to address this vulnerability. The mitigation strategy involves updating to version 70.0.23 or later, which includes proper input validation and sanitization of session data received from OpenID providers. Additionally, administrators should review and audit session files for any signs of unauthorized modifications and consider implementing additional monitoring controls to detect anomalous session behavior that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to ensure that all components within the cPanel environment remain protected against similar injection attacks.