CVE-2016-4806 in Web2py
Summary
by MITRE
Web2py versions 2.14.5 and below was affected by Local File Inclusion vulnerability, which allows a malicious intended user to read/access web server sensitive files.
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Analysis
by VulDB Data Team • 06/24/2024
The CVE-2016-4806 vulnerability represents a critical local file inclusion flaw discovered in Web2py version 2.14.5 and earlier releases, fundamentally compromising the security posture of affected web applications. This vulnerability stems from inadequate input validation within the web framework's file handling mechanisms, allowing attackers to manipulate file access parameters and gain unauthorized access to sensitive server resources. The flaw specifically manifests when the application fails to properly sanitize user-supplied input that determines file paths or includes, creating an exploitable condition where arbitrary file access becomes possible. Such vulnerabilities are particularly dangerous in web applications as they can enable attackers to read system files, configuration data, and potentially sensitive information that should remain protected within the server environment.
The technical exploitation of this vulnerability occurs through manipulation of file inclusion parameters within the Web2py framework, where attackers can construct malicious requests that bypass normal file access controls. The vulnerability aligns with CWE-22, which categorizes improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks. Attackers can leverage this flaw to access files such as database configuration files, application source code, system configuration files, and potentially even credential storage locations. The impact extends beyond simple information disclosure as it can provide attackers with sufficient information to conduct further attacks, including privilege escalation, system compromise, or data exfiltration. This type of vulnerability represents a fundamental breakdown in the principle of least privilege, where user input directly influences system file access without proper sanitization or validation.
From an operational standpoint, the exploitation of CVE-2016-4806 can result in significant security breaches affecting organizations that rely on Web2py applications. The vulnerability enables attackers to access sensitive data that may include database connection strings, cryptographic keys, user credentials, and application logic that could be used for subsequent attacks. This exposure can lead to complete system compromise, data loss, regulatory compliance violations, and reputational damage. The vulnerability also provides attackers with potential attack vectors for lateral movement within networks, as access to application configuration files often reveals network topology information and system interdependencies. Organizations running vulnerable versions of Web2py face increased risk of successful exploitation, particularly in environments where the framework handles sensitive data processing or user authentication functions.
Mitigation strategies for CVE-2016-4806 primarily focus on immediate version upgrades to Web2py 2.14.6 or later, which contain patches addressing the file inclusion vulnerability. Security administrators should implement comprehensive input validation mechanisms, ensuring that all file access operations properly sanitize user input and validate file paths against allowed directories. Network segmentation and access controls should be enforced to limit exposure of vulnerable applications to untrusted networks. Additionally, organizations should conduct thorough security assessments of their Web2py applications, reviewing file access patterns and implementing proper file inclusion controls that prevent path traversal attacks. The remediation process should include regular security updates, vulnerability scanning, and monitoring for potential exploitation attempts. Implementation of web application firewalls and security monitoring solutions can provide additional layers of protection against exploitation attempts while ensuring compliance with security standards such as those outlined in the OWASP Top Ten and NIST cybersecurity frameworks.