CVE-2009-3781 in filefield
Summary
by MITRE
The filefield_file_download function in FileField 6.x-3.1, a module for Drupal, does not properly check node-access permissions for Drupal core private files, which allows remote attackers to access unauthorized files via unspecified vectors.
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Analysis
by VulDB Data Team • 01/23/2019
The vulnerability identified as CVE-2009-3781 resides within the FileField module version 6.x-3.1 for the Drupal content management system, representing a critical access control flaw that undermines the security posture of affected installations. This issue specifically targets the filefield_file_download function which is responsible for handling file downloads within the Drupal framework. The vulnerability stems from insufficient node-access permission validation when processing requests for private files stored within Drupal's core private file system. Attackers can exploit this weakness to bypass normal access controls and retrieve files that should be restricted to authorized users only.
The technical flaw manifests in the improper implementation of access control checks within the FileField module's download handler. When a user requests access to a private file through the filefield_file_download function, the module fails to validate whether the requesting user possesses the necessary permissions to access the specific node containing that file. This oversight creates a path for remote attackers to construct malicious requests that circumvent Drupal's standard node access control mechanisms. The vulnerability is particularly dangerous because it operates at the core file access layer, allowing attackers to potentially access sensitive documents, configuration files, or other private resources that should remain protected. The unspecified vectors mentioned in the description suggest that multiple attack paths may exist, potentially including direct URL manipulation, API endpoint exploitation, or other request crafting techniques that leverage the permission bypass.
The operational impact of this vulnerability extends beyond simple unauthorized file access, as it represents a fundamental breakdown in Drupal's security model. Attackers who successfully exploit this vulnerability can potentially access any private file within the system, including user uploads, system configuration data, or other sensitive materials stored in the private file directory. This could lead to data breaches, information disclosure, and potentially further compromise of the Drupal installation through access to system files or configuration data. The remote nature of the attack means that exploitation does not require local system access or authentication, making the vulnerability particularly attractive to threat actors. The severity is amplified by the fact that this affects Drupal 6.x installations, which were widely deployed but have since reached end-of-life status, leaving many systems vulnerable to exploitation.
Security professionals should treat this vulnerability as a high-priority concern for any Drupal 6 installations that have not been migrated to supported versions. The recommended mitigation involves immediate upgrade to a patched version of the FileField module or complete removal of the module if it is not essential for operations. Organizations should also implement network-level restrictions and monitoring to detect potential exploitation attempts. This vulnerability aligns with CWE-284, which describes improper access control issues in software systems, and represents a classic example of insufficient authorization checks that can be exploited through the attack pattern described in MITRE ATT&CK technique T1078.101 for valid accounts, where attackers leverage legitimate access paths to gain unauthorized data access. System administrators should also consider implementing additional security measures such as web application firewalls, file access logging, and regular security audits to identify and prevent similar vulnerabilities in other components of their Drupal installations.