CVE-2011-4069 in PacketFence
Summary
by MITRE
html/admin/login.php in PacketFence before 3.0.2 allows remote attackers to conduct LDAP injection attacks and consequently bypass authentication via a crafted username.
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Analysis
by VulDB Data Team • 12/31/2019
The vulnerability identified as CVE-2011-4069 represents a critical authentication bypass flaw in PacketFence versions prior to 3.0.2. This issue specifically affects the html/admin/login.php component which handles administrative login functionality. The vulnerability stems from insufficient input validation and sanitization of user-provided credentials, particularly the username field, which creates an avenue for malicious actors to exploit the Lightweight Directory Access Protocol (LDAP) authentication mechanism. Attackers can craft specially formatted usernames that manipulate the LDAP query structure, allowing them to bypass the authentication process entirely without proper credentials.
The technical implementation of this vulnerability falls under CWE-90, which describes Improper Neutralization of Special Elements used in an LDAP Query, and aligns with the broader category of injection vulnerabilities. When a malicious user submits a crafted username containing LDAP injection payloads, the system fails to properly escape or sanitize special characters that have significance within LDAP query syntax. This allows attackers to manipulate the underlying LDAP search operations that PacketFence uses to validate user credentials against directory services. The flaw essentially enables attackers to inject arbitrary LDAP filter components that can alter the authentication logic, potentially allowing access to administrative functions through unauthorized means.
From an operational perspective, this vulnerability creates a severe security risk for organizations relying on PacketFence for network access control and authentication management. Successful exploitation would enable remote attackers to gain administrative privileges without legitimate credentials, potentially leading to complete network compromise. The impact extends beyond simple authentication bypass, as administrative access typically provides the ability to modify network policies, access sensitive configuration data, and potentially pivot to other systems within the network infrastructure. This vulnerability is particularly dangerous because it operates at the authentication layer, meaning that once exploited, attackers can maintain persistent access and escalate privileges without detection.
The attack vector for this vulnerability is straightforward and requires minimal technical expertise to exploit. Remote attackers need only submit a specially crafted username to the login interface, with no additional authentication requirements. This makes the vulnerability particularly attractive to threat actors and increases the likelihood of successful exploitation. Organizations should consider implementing mitigations such as upgrading to PacketFence 3.0.2 or later versions where the vulnerability has been patched, along with implementing additional monitoring and logging of authentication attempts. Network segmentation and access controls should also be reviewed to limit the potential impact of successful exploitation. The vulnerability demonstrates the critical importance of input validation and sanitization in authentication systems, aligning with ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing to highlight the broader attack implications.
The remediation approach for this vulnerability involves implementing proper input sanitization and escaping mechanisms for LDAP queries. Organizations should ensure that all user inputs are properly validated and that special characters used in LDAP syntax are appropriately escaped or filtered. The fix typically involves updating the PacketFence software to version 3.0.2 or later, which includes proper sanitization of LDAP search filters. Additionally, implementing proper logging and monitoring of authentication attempts can help detect potential exploitation attempts. Security controls should also include regular vulnerability assessments and penetration testing to identify similar issues in other authentication systems. The vulnerability serves as a reminder of the importance of following secure coding practices and the potential consequences of inadequate input validation in security-critical components.