CVE-2012-4741 in PacketFence
Summary
by MITRE
The RADIUS extension in PacketFence before 3.3.0 uses a different user name than is used for authentication for users with custom VLAN assignment extensions, which allows remote attackers to spoof user identities via the User-Name RADIUS attribute.
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Analysis
by VulDB Data Team • 02/20/2019
The vulnerability described in CVE-2012-4741 affects PacketFence versions prior to 3.3.0 and relates to a critical identity spoofing issue within the RADIUS extension component. This flaw specifically impacts network access control systems that rely on RADIUS protocol for authentication and authorization. The vulnerability stems from an inconsistent handling of user identification between the authentication process and the VLAN assignment mechanism, creating a pathway for malicious actors to manipulate network access controls. The RADIUS protocol is fundamental to network security infrastructure, serving as the backbone for authenticating users and authorizing network access in enterprise environments. When implemented incorrectly, as demonstrated in this vulnerability, it can undermine the entire security posture of network access control systems.
The technical flaw manifests in the mismatch between user identification used during authentication versus the identification employed for custom VLAN assignment extensions. Specifically, when users are assigned custom VLANs through RADIUS extensions, PacketFence utilizes a different username for the VLAN assignment process compared to the one used for authentication purposes. This discrepancy creates a potential attack vector where remote adversaries can manipulate the User-Name RADIUS attribute to present a false identity. The User-Name attribute in RADIUS is critical for identifying users and determining their access privileges, making this vulnerability particularly dangerous as it allows attackers to impersonate legitimate users within the network infrastructure.
The operational impact of this vulnerability extends beyond simple identity theft, as it can enable unauthorized network access and privilege escalation within environments relying on PacketFence for network access control. Attackers exploiting this flaw could potentially gain access to network segments that should be restricted to specific users or groups, undermining the principle of least privilege and network segmentation. This vulnerability directly affects network security policies and could allow attackers to move laterally within a network, access sensitive resources, or disrupt network operations. The implications are particularly severe in environments where network access control is critical for compliance with security standards such as those outlined in the NIST Cybersecurity Framework or ISO/IEC 27001, where proper authentication and authorization mechanisms are essential for maintaining security boundaries.
The vulnerability aligns with CWE-287 which addresses improper authentication issues, and can be mapped to ATT&CK technique T1566 for social engineering attacks that leverage identity spoofing. Organizations using PacketFence should immediately upgrade to version 3.3.0 or later to remediate this vulnerability. Additional mitigations include implementing network segmentation to limit the impact of potential exploitation, monitoring RADIUS authentication logs for anomalous User-Name attribute values, and conducting regular security assessments of network access control systems. The vulnerability demonstrates the importance of maintaining consistency in identity management processes across authentication and authorization systems, as inconsistencies can create exploitable gaps in network security architecture. Proper configuration management and regular security updates are essential practices to prevent similar vulnerabilities from compromising network infrastructure security.