CVE-2018-6188 in Django
Summary
by MITRE
django.contrib.auth.forms.AuthenticationForm in Django 2.0 before 2.0.2, and 1.11.8 and 1.11.9, allows remote attackers to obtain potentially sensitive information by leveraging data exposure from the confirm_login_allowed() method, as demonstrated by discovering whether a user account is inactive.
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Analysis
by VulDB Data Team • 02/03/2023
The vulnerability identified as CVE-2018-6188 affects the Django web framework's authentication system, specifically the AuthenticationForm component that handles user login attempts. This issue exists in Django versions 2.0 before 2.0.2 and 1.11.8 and 1.11.9, creating a significant information disclosure risk that can be exploited by remote attackers. The flaw stems from how the confirm_login_allowed() method exposes sensitive user account status information during authentication attempts, allowing adversaries to determine whether specific user accounts are inactive or disabled.
The technical implementation of this vulnerability occurs within the Django authentication flow where the AuthenticationForm class processes login requests and calls confirm_login_allowed() to validate user credentials. When this method is invoked, it inadvertently reveals information about user account states through timing variations or error responses that differ between active and inactive accounts. Attackers can exploit this by attempting to authenticate with various user accounts and observing the system's response patterns, thereby gaining knowledge about which accounts are inactive or disabled without proper authorization. This type of information leakage represents a classic case of timing-based side-channel attacks where the system's behavior reveals sensitive data about its internal state.
The operational impact of CVE-2018-6188 extends beyond simple information disclosure, as it enables attackers to conduct user enumeration attacks against authentication systems. This vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and can be categorized under the ATT&CK technique T1087.001 for Account Discovery. An attacker who successfully exploits this vulnerability gains the ability to map valid user accounts within the system, which can then be used for more sophisticated attacks such as targeted credential stuffing, brute force attempts against inactive accounts, or social engineering campaigns. The exposure of account status information can also enable attackers to focus their efforts on accounts that are more likely to be valid targets, significantly increasing the efficiency of their attack campaigns.
Organizations running affected Django versions should immediately implement the available patches, specifically upgrading to Django 2.0.2 or 1.11.9, which contain the necessary fixes for this vulnerability. The mitigation strategy involves not only applying the software updates but also implementing additional security controls such as rate limiting on authentication attempts, monitoring for unusual login patterns, and ensuring that authentication systems provide consistent error responses regardless of account status. Security teams should also consider implementing account lockout mechanisms and multi-factor authentication to reduce the overall risk surface. The vulnerability demonstrates the importance of proper error handling in authentication systems and highlights how seemingly minor implementation details can create significant security risks. Organizations should conduct thorough security assessments of their authentication flows and ensure that all user-facing error messages provide minimal information to prevent similar information disclosure issues from occurring in other components of their web applications.