CVE-2008-4789 in Drupal
Summary
by MITRE
The validation functionality in the core upload module in Drupal 6.x before 6.5 allows remote authenticated users to bypass intended access restrictions and "attach files to content," related to a "logic error."
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Analysis
by VulDB Data Team • 10/13/2018
The vulnerability identified as CVE-2008-4789 represents a critical authorization bypass flaw within Drupal 6.x core upload module prior to version 6.5. This issue stems from a fundamental logic error in the file validation mechanism that permits authenticated users to circumvent intended access controls. The vulnerability specifically affects the core upload functionality where Drupal's permission system fails to properly validate user privileges during file attachment operations. The flaw enables attackers to exploit the system's validation logic and attach files to content without possessing the necessary authorization rights, effectively undermining the platform's security model.
The technical implementation of this vulnerability resides in the upload module's permission checking routines where a logic error prevents proper validation of user capabilities. When users attempt to upload files and attach them to content, the system should verify that the authenticated user possesses the appropriate permissions to perform such actions. However, due to the flawed logic implementation, the validation process fails to properly enforce access restrictions, allowing users to bypass these controls entirely. This logic error manifests as a failure in the conditional statements or permission checking mechanisms that should have prevented unauthorized file attachment operations. The vulnerability is particularly concerning because it operates within the core upload functionality, making it difficult to patch or isolate from other system components.
From an operational impact perspective, this vulnerability creates significant security risks for Drupal 6.x installations that remain unpatched. Attackers with basic authenticated user accounts can exploit this flaw to attach malicious files to content, potentially leading to various downstream attacks including cross-site scripting, remote code execution, or data manipulation. The unauthorized file attachment capability allows threat actors to bypass content security measures and upload files that could contain malicious payloads or exploit other system vulnerabilities. This vulnerability directly impacts the integrity and confidentiality of content management operations, as users can manipulate content attachments without proper authorization. The flaw essentially creates a backdoor mechanism that undermines the platform's access control model and could enable attackers to escalate privileges or compromise other system components through file-based attacks.
The vulnerability aligns with CWE-284, which addresses improper access control issues, and demonstrates characteristics consistent with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. Organizations should implement immediate mitigation strategies including applying the official Drupal 6.5 security patch that addresses the specific logic error in the upload validation module. System administrators should also consider implementing additional monitoring controls to detect unauthorized file attachment activities and review user permissions regularly. Network segmentation and access control policies should be enforced to limit the potential impact of such vulnerabilities. The patch for this vulnerability specifically corrects the permission validation logic to ensure that only users with appropriate privileges can attach files to content, thereby restoring the intended security controls within the Drupal platform's core functionality.