CVE-2019-13264 in DIR-825AC G1
Summary
by MITRE
D-link DIR-825AC G1 devices have Insufficient Compartmentalization between a host network and a guest network that are established by the same device. In order to transfer data from the host network to the guest network, the sender joins and then leaves an IGMP group. After it leaves, the router (following the IGMP protocol) creates an IGMP Membership Query packet with the Group IP and sends it to both the Host and the Guest networks. The data is transferred within the Group IP field, which is completely controlled by the sender.
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Analysis
by VulDB Data Team • 12/07/2023
The CVE-2019-13264 vulnerability affects D-Link DIR-825AC G1 wireless routers and represents a significant security flaw in network segmentation mechanisms. This vulnerability stems from insufficient compartmentalization between host and guest networks within the same device, creating a fundamental breach in network isolation principles that are critical for maintaining security boundaries. The flaw specifically manifests in how the router handles Internet Group Management Protocol (IGMP) operations, which are designed to manage multicast group memberships in IP networks. When a device attempts to transfer data from the host network to the guest network, the system requires the sender to join and then leave an IGMP group as part of the data transfer process. This seemingly innocuous operation creates a dangerous condition where the router's IGMP Membership Query packet contains the Group IP address that serves as the vehicle for data transmission, leaving the system vulnerable to manipulation by malicious actors. The vulnerability directly relates to CWE-284, which addresses improper access control mechanisms, and specifically targets the inadequate separation of network zones. The attack vector operates through the manipulation of IGMP protocol behavior, where the Group IP field becomes a conduit for unauthorized data transfer between network segments.
The technical exploitation of this vulnerability occurs when an attacker on the host network can control the Group IP address field within the IGMP Membership Query packet that is broadcast to both host and guest networks. This allows for arbitrary data transfer between networks that should remain isolated, effectively bypassing the security controls designed to separate these segments. The router's implementation of IGMP protocol handling creates a situation where the Group IP address field is completely controlled by the sender, enabling potential attackers to inject data into the guest network without proper authentication or authorization. This vulnerability essentially allows for a form of network tunneling that violates fundamental security principles of network segmentation, where the boundary between host and guest networks becomes permeable. The flaw demonstrates a critical failure in the router's network isolation implementation, as it fails to properly validate or restrict the Group IP addresses that can be used for inter-network communication.
The operational impact of this vulnerability is substantial as it enables attackers to perform unauthorized data exfiltration from the host network to the guest network, potentially allowing for information leakage, lateral movement, or even complete network compromise. The vulnerability can be exploited to transfer malicious payloads between network segments, undermining the security posture of networks that rely on guest network isolation for protection. Network administrators may be unaware of this unauthorized data transfer mechanism, as it operates through legitimate IGMP protocol behavior that appears normal to network monitoring systems. The implications extend beyond simple data transfer, as this vulnerability can enable attackers to establish persistence within network segments, conduct reconnaissance activities, or even facilitate more sophisticated attacks that exploit the compromised network boundaries. The vulnerability affects all users of the affected D-Link device models and represents a significant risk to organizations that rely on guest network segmentation as part of their security strategy, potentially violating standards such as those outlined in the NIST Cybersecurity Framework and ISO/IEC 27001 for network security controls.
Mitigation strategies for CVE-2019-13264 should focus on implementing network segmentation controls that prevent the IGMP group membership operations from creating unauthorized data transfer paths between network segments. Network administrators should consider disabling IGMP snooping or implementing strict IGMP filtering rules that prevent cross-network communication through IGMP group operations. The most effective approach involves updating firmware to address the underlying implementation flaw in the router's IGMP handling mechanism, which would require D-Link to release patched firmware versions. Organizations should also implement network monitoring solutions that can detect anomalous IGMP traffic patterns and unauthorized data transfers between network segments. Additional defensive measures include implementing strict access control lists, disabling unnecessary network services, and ensuring that guest networks are properly isolated through multiple security layers. The vulnerability highlights the importance of proper protocol implementation and network boundary enforcement, aligning with ATT&CK technique T1046 for network service scanning and T1071.004 for application layer protocols, as it enables unauthorized network communication through legitimate protocol mechanisms. Security teams should also consider implementing network behavior analytics to detect potential exploitation attempts and ensure that network segmentation policies are properly enforced across all network devices.