CVE-2017-9475 in XFINITY WiFi Home Hotspot
Summary
by MITRE
Comcast XFINITY WiFi Home Hotspot devices allow remote attackers to spoof the identities of Comcast customers via a forged MAC address.
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Analysis
by VulDB Data Team • 11/02/2019
The vulnerability identified as CVE-2017-9475 affects Comcast XFINITY WiFi Home Hotspot devices, representing a significant security flaw in the authentication mechanisms of residential wireless infrastructure. This issue stems from insufficient validation of device identity within the network access control system, allowing malicious actors to exploit the lack of proper MAC address verification. The vulnerability specifically targets the authentication process that occurs when devices attempt to connect to the Comcast network, creating a pathway for unauthorized users to gain legitimate network access by simply mimicking authorized device identifiers.
The technical implementation of this flaw resides in the hotspot device's failure to properly validate the Media Access Control (MAC) address presented during the authentication handshake process. When a device attempts to connect to the Comcast network, the system should verify that the MAC address corresponds to a legitimate authorized device within the customer's account. However, the vulnerability allows attackers to forge MAC addresses that appear to belong to legitimate Comcast customers, effectively bypassing the network access controls. This weakness operates at the network layer of the OSI model, specifically impacting the data link layer authentication mechanisms that should prevent unauthorized network access. The flaw represents a classic case of inadequate input validation and authentication, aligning with CWE-287 which addresses improper authentication issues in network protocols and systems.
The operational impact of this vulnerability extends beyond simple unauthorized network access, creating potential for broader security compromise within the affected network environment. An attacker who successfully spoofs a legitimate MAC address can gain full access to the Comcast customer's network resources, potentially accessing personal devices, sensitive data, and other network-connected systems. This type of attack can be particularly dangerous in residential environments where personal information and connected IoT devices may be present. The vulnerability enables persistent unauthorized access, as the forged MAC address can be reused indefinitely until the legitimate device is removed from the network or the authentication system is updated. According to ATT&CK framework, this represents a technique categorized under T1076 - Network Logon Scripts, where adversaries establish persistent access through legitimate credentials or identities.
Mitigation strategies for this vulnerability should focus on strengthening the authentication mechanisms within the hotspot devices and implementing additional security layers to prevent MAC address spoofing. Network administrators should consider implementing MAC address filtering combined with more robust authentication methods such as 802.1X authentication or multi-factor authentication. The devices should be configured to validate MAC addresses against a centralized database of authorized devices rather than relying solely on the presented address. Additionally, network segmentation should be implemented to limit the potential damage from successful exploitation. Regular monitoring of network access logs for suspicious MAC address patterns and implementing network intrusion detection systems can help identify and respond to exploitation attempts. The vulnerability also highlights the importance of secure configuration management and regular firmware updates to address known security flaws in network infrastructure devices. Organizations should also consider implementing network access control policies that require additional authentication factors beyond simple MAC address validation to prevent similar attacks from succeeding.