CVE-2016-10848 in cPanel
Summary
by MITRE
cPanel before 11.54.0.4 allows arbitrary file-overwrite operations in scripts/quotacheck (SEC-81).
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Analysis
by VulDB Data Team • 11/20/2023
The vulnerability identified as CVE-2016-10848 represents a critical file overwrite flaw in cPanel versions prior to 11.54.0.4 that specifically affects the scripts/quotacheck component. This vulnerability falls under the category of insecure file handling and privilege escalation, creating a significant risk for systems running affected cPanel versions. The issue stems from insufficient input validation and inadequate file permission controls within the quotacheck script, which is responsible for monitoring and managing disk quotas for user accounts. When exploited, this vulnerability allows attackers to overwrite arbitrary files on the system, potentially leading to complete system compromise or data destruction.
The technical exploitation of this vulnerability occurs through the quotacheck script's failure to properly validate file paths and permissions during file operations. Attackers can manipulate the script's behavior by crafting specific inputs that cause the system to write to unintended locations, bypassing normal file access controls and security boundaries. This flaw is particularly dangerous because quotacheck typically runs with elevated privileges, allowing an attacker to overwrite critical system files, configuration files, or even executable binaries. The vulnerability's classification aligns with CWE-22, which addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw also demonstrates characteristics of CWE-73, which covers external control of filename or path, indicating that user-controllable inputs are directly influencing file system operations without proper sanitization.
The operational impact of CVE-2016-10848 extends far beyond simple file overwrite capabilities, as it provides attackers with a powerful primitive for system compromise and persistence. An attacker who successfully exploits this vulnerability can overwrite critical system files such as configuration files, log files, or even system binaries, potentially leading to complete system takeover. The attack vector typically involves gaining access to a low-privilege account or web application that can execute the quotacheck script, then manipulating the script's parameters to target sensitive files. This vulnerability is particularly concerning in shared hosting environments where multiple users operate on the same cPanel instance, as it could enable one user to compromise another user's files or even the entire system. The attack can be executed through various means including web-based interfaces, command-line execution, or through compromised web applications that interact with cPanel services. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1078 (Valid Accounts) as it exploits legitimate system accounts and scripts to achieve unauthorized file operations.
Mitigation strategies for CVE-2016-10848 primarily focus on immediate patching and system hardening measures. The most effective solution is upgrading to cPanel version 11.54.0.4 or later, which includes proper input validation and enhanced file access controls within the quotacheck script. System administrators should also implement strict file permission controls and regularly audit script execution privileges to prevent unauthorized file modifications. Additional protective measures include implementing network segmentation, monitoring for unusual file modification patterns, and ensuring that the quotacheck script runs with minimal necessary privileges. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates. The vulnerability's impact is further reduced by implementing proper access controls and ensuring that only authorized personnel can execute system management scripts. Security monitoring should specifically track file system operations involving the quotacheck script and any attempts to overwrite system-critical files, as these activities may indicate exploitation attempts. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other system components that might present similar attack surfaces to the one described in CVE-2016-10848.