CVE-2016-2048 in Django
Summary
by MITRE
Django 1.9.x before 1.9.2, when ModelAdmin.save_as is set to True, allows remote authenticated users to bypass intended access restrictions and create ModelAdmin objects via the "Save as New" option when editing objects and leveraging the "change" permission.
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Analysis
by VulDB Data Team • 07/06/2022
The vulnerability identified as CVE-2016-2048 affects Django versions 1.9.x prior to 1.9.2 and represents a significant access control flaw within the Django admin interface. This issue specifically impacts applications that utilize ModelAdmin with the save_as functionality enabled, creating a path for authenticated attackers to circumvent intended security controls. The vulnerability stems from improper permission checking during the "Save as New" operation, which should have restricted access based on user permissions but failed to enforce these controls properly.
The technical flaw manifests when ModelAdmin.save_as is configured to True, allowing users to duplicate existing objects through the admin interface. Under normal circumstances, this feature should only be accessible to users who possess both the necessary change permissions for the specific model and appropriate administrative privileges. However, the vulnerability enables authenticated users with merely the "change" permission to exploit this functionality and create new objects, effectively bypassing the intended access restrictions that should prevent unauthorized object creation. This represents a classic privilege escalation issue where a user can perform actions beyond their designated permissions.
The operational impact of this vulnerability extends beyond simple unauthorized object creation, as it fundamentally undermines the security model of Django applications that rely on proper permission controls. Attackers can leverage this flaw to add new records to databases through the admin interface, potentially leading to data integrity issues, information disclosure, or even further exploitation opportunities within the application. The vulnerability affects any Django application that uses ModelAdmin with save_as enabled and has users with change permissions, making it particularly concerning for applications with multiple user roles and varying permission levels. This issue falls under the CWE-284 access control weakness category, specifically addressing improper access control mechanisms where permissions are not properly enforced during object duplication operations.
Security professionals should note that this vulnerability demonstrates the importance of proper permission validation in web application frameworks, particularly in administrative interfaces where elevated privileges are commonly required. The flaw enables attackers to exploit the administrative interface's object duplication functionality to create unauthorized entries, potentially leading to data corruption or unauthorized access to sensitive information. Organizations running affected Django versions should immediately apply the patch released in Django 1.9.2, which addresses the improper permission checking during the save_as operation. The mitigation strategy involves updating to the patched version and reviewing existing ModelAdmin configurations to ensure that appropriate access controls are maintained for all administrative functions, particularly those involving object duplication and creation operations.
This vulnerability aligns with ATT&CK technique T1078 legitimate credentials, as it allows attackers to leverage existing user permissions to perform unauthorized actions within the application's administrative interface. The issue highlights the critical need for comprehensive security testing of administrative features and proper validation of user permissions across all application functions. Organizations should implement regular security assessments of their Django applications to identify similar permission bypass vulnerabilities, particularly focusing on administrative interfaces and object manipulation features. The patch for this vulnerability specifically addresses the missing permission checks in the ModelAdmin.save_as functionality, ensuring that proper authorization is enforced before allowing users to create new objects through the save as new option.