CVE-2016-10829 in cPanel
Summary
by MITRE
cPanel before 55.9999.141 allows arbitrary file-read operations because of a multipart form processing error (SEC-99).
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Analysis
by VulDB Data Team • 11/20/2023
The vulnerability identified as CVE-2016-10829 represents a critical security flaw in cPanel software versions prior to 55.9999.141, specifically related to improper handling of multipart form data processing. This vulnerability falls under the category of insecure direct object reference and arbitrary file read operations, creating a significant risk for systems that rely on cPanel for web hosting management. The issue stems from how the application processes multipart form data, which is commonly used for file uploads and form submissions containing binary data. When cPanel encounters multipart form data, it fails to properly validate or sanitize the input parameters that specify file paths or object references, allowing attackers to manipulate these parameters and access files outside the intended directory structure. This type of vulnerability is particularly dangerous because it can be exploited to read sensitive files such as configuration files, database credentials, user information, and other system files that should remain protected. The vulnerability operates at the application layer and can be exploited through web-based interfaces, making it accessible to attackers who can craft malicious requests to manipulate the form processing logic.
The technical exploitation of this vulnerability involves crafting specially formatted multipart form requests that manipulate the file path parameters used by cPanel's internal processing functions. Attackers can leverage this flaw to perform directory traversal attacks or directly reference files outside the web root directory through the form processing mechanism. The vulnerability is particularly concerning because cPanel is widely used for managing web hosting environments, making it a prime target for attackers seeking to gain unauthorized access to sensitive hosting data. This flaw enables attackers to read arbitrary files on the server, potentially exposing database connection strings, user authentication details, configuration files containing system secrets, and other confidential information. The impact extends beyond simple information disclosure, as the ability to read system files can lead to further exploitation opportunities including privilege escalation, credential theft, and system compromise. According to CWE classification, this vulnerability maps to CWE-22: Improper Limitation of a Pathname to a Restricted Directory, which specifically addresses the issue of insufficient input validation leading to unauthorized file access. The vulnerability also aligns with ATT&CK technique T1083: File and Directory Discovery, as it enables adversaries to enumerate and access files on the compromised system.
The operational impact of this vulnerability is severe for organizations using affected cPanel versions, as it provides attackers with the capability to perform unauthorized file reads across the entire file system. System administrators may be unaware of the exploitation until significant damage has occurred, as the vulnerability can be leveraged to access multiple types of sensitive information including user accounts, database credentials, and system configuration files. The attack surface is particularly broad since cPanel is used extensively across hosting providers and enterprise environments, meaning that a single vulnerable instance can provide access to numerous systems. Organizations that have not updated to the patched version are at risk of credential theft, data breaches, and potential system compromise. The vulnerability can be exploited through simple web-based attacks without requiring special privileges or advanced technical knowledge, making it particularly dangerous for widespread exploitation. Recovery from such an attack typically requires system compromise assessment, credential rotation, and comprehensive security auditing. The remediation process involves updating to cPanel version 55.9999.141 or later, which includes proper input validation and sanitization of multipart form data parameters. Additionally, organizations should implement network monitoring to detect suspicious file access patterns and consider implementing additional security controls such as web application firewalls and access controls to limit exposure. The vulnerability demonstrates the importance of proper input validation in web applications and highlights how seemingly minor flaws in form processing can lead to major security breaches.