CVE-2016-10819 in cPanel
Summary
by MITRE
In cPanel before 57.9999.54, user log files become world-readable when rotated by cpanellogd (SEC-125).
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Analysis
by VulDB Data Team • 11/14/2023
The vulnerability identified as CVE-2016-10819 affects cPanel versions prior to 57.9999.54 and represents a critical access control flaw that compromises the confidentiality of user data. This issue specifically impacts the cpanellogd daemon responsible for rotating log files on cPanel servers, creating a persistent security weakness that can be exploited by unauthorized users. The vulnerability stems from improper file permission handling during the log rotation process, where log files that should remain accessible only to their respective owners become globally readable, exposing sensitive information to all users on the system.
The technical flaw occurs within the cpanellogd service implementation where log file rotation operations fail to properly reset file permissions after the rotation process completes. When log files are rotated, the system should ensure that newly created log files maintain appropriate ownership and permission settings that restrict access to the file owner only. However, in affected versions, the rotation process leaves these files with world-readable permissions, typically set to 0644 or similar, allowing any user on the system to access the contents. This represents a direct violation of the principle of least privilege and creates an information disclosure vulnerability that can be leveraged for various malicious activities.
The operational impact of this vulnerability extends beyond simple information disclosure, as log files often contain sensitive data including user credentials, system access patterns, application errors, and potentially confidential business information. Attackers can exploit this weakness to gather intelligence about system users, identify potential attack vectors, and extract credentials or session information that may lead to further compromise. The vulnerability affects all users on the system, making it particularly dangerous in shared hosting environments where multiple customers share the same server infrastructure. This weakness can be exploited by any user with basic system access, making it a significant risk to server security and compliance with data protection regulations.
The vulnerability aligns with CWE-732: Incorrect Permission Assignment for Critical Resource, which specifically addresses situations where critical system resources are assigned incorrect permissions that allow unauthorized access. From an attack perspective, this flaw maps to several MITRE ATT&CK techniques including T1005: Data from Local System and T1083: File and Directory Discovery, as attackers can systematically enumerate and access log files containing sensitive information. Organizations should implement immediate mitigation measures including updating to cPanel version 57.9999.54 or later, manually correcting permissions on existing log files, and implementing monitoring for unauthorized access to log directories. Additionally, security teams should conduct comprehensive audits of all log file permissions and implement automated processes to ensure proper access controls are maintained during routine system operations, as this vulnerability demonstrates the critical importance of maintaining proper file permission hygiene in web hosting environments.