CVE-2018-11385 in Symfony
Summary
by MITRE
An issue was discovered in the Security component in Symfony 2.7.x before 2.7.48, 2.8.x before 2.8.41, 3.3.x before 3.3.17, 3.4.x before 3.4.11, and 4.0.x before 4.0.11. A session fixation vulnerability within the "Guard" login feature may allow an attacker to impersonate a victim towards the web application if the session id value was previously known to the attacker.
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Analysis
by VulDB Data Team • 03/27/2023
The vulnerability identified as CVE-2018-11385 represents a critical session fixation weakness within Symfony's Security component that affects multiple version branches including 2.7.x through 4.0.x. This issue specifically targets the Guard authentication mechanism, which is a modern approach to authentication in Symfony applications that allows developers to create custom authentication systems using guard classes. The vulnerability stems from improper session management during the authentication process where the system fails to regenerate session identifiers upon successful authentication, creating an exploitable condition that allows attackers to maintain persistent access to user sessions.
The technical flaw manifests when an attacker first establishes a session with a known session identifier and then attempts to authenticate through the Guard login feature. The vulnerability occurs because the Symfony security component does not properly invalidate or regenerate the session identifier during the authentication process, allowing the attacker to reuse the pre-established session ID even after successful authentication. This creates a scenario where an authenticated session can be hijacked and maintained by an attacker who possesses the original session identifier, effectively bypassing normal authentication mechanisms. The vulnerability is classified under CWE-384 as "Session Fixation" and represents a direct violation of secure session management principles that should ensure session identifiers are regenerated upon authentication events.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables persistent session hijacking attacks that can remain undetected for extended periods. Attackers who obtain a valid session identifier can maintain access to victim accounts indefinitely, potentially gaining access to sensitive data, performing unauthorized transactions, or using compromised accounts for further attacks within the application ecosystem. The vulnerability is particularly dangerous in environments where session identifiers are predictable or have been previously exposed through other means such as network sniffing, logging, or insecure transmission channels. This issue directly maps to attack techniques described in the MITRE ATT&CK framework under T1548.003 for "Abuse Elevation Control Mechanism" and T1078.004 for "Valid Accounts: Default Accounts" when attackers leverage pre-established session identifiers to maintain access.
Organizations affected by this vulnerability should immediately implement comprehensive mitigation strategies that include upgrading to the patched versions of Symfony where the session fixation issue has been resolved. The recommended approach involves upgrading to Symfony 2.7.48, 2.8.41, 3.3.17, 3.4.11, or 4.0.11 respectively, which contain the necessary patches to ensure proper session regeneration during authentication events. Additionally, administrators should implement proper session management practices including automatic session invalidation upon authentication, secure session cookie attributes such as HttpOnly and Secure flags, and regular session cleanup processes. Organizations should also consider implementing additional security controls such as multi-factor authentication, session timeout mechanisms, and monitoring for suspicious authentication patterns that could indicate session hijacking attempts. The vulnerability serves as a reminder of the critical importance of proper session management in web applications and the necessity of following security best practices for authentication components.