CVE-2016-1337 in EPC3928
Summary
by MITRE
Cisco EPC3928 devices allow remote attackers to obtain sensitive configuration and credential information by making requests during the early part of the boot process, related to a "Boot Information Disclosure" issue, aka Bug ID CSCux17178.
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Analysis
by VulDB Data Team • 06/17/2024
The Cisco EPC3928 is a residential gateway device that serves as a critical component in many home and small office networks, providing broadband connectivity and various networking services. This device operates as a modem-router combination that handles internet protocol traffic and manages local network communications for end users. The vulnerability under examination represents a significant security flaw that affects the device's boot process and exposes sensitive operational data to unauthorized remote actors. The affected device model is particularly concerning because it operates in unattended environments where physical security measures are often minimal, making remote exploitation particularly dangerous.
The technical flaw manifests during the early stages of the device's boot process when it fails to properly restrict access to critical system information and configuration parameters. This vulnerability specifically relates to a "Boot Information Disclosure" issue where the device's boot sequence does not adequately authenticate or authorize access to sensitive data that should remain protected until the system reaches a stable operational state. The flaw allows attackers to make specific requests during this vulnerable window to obtain credentials, configuration files, and other sensitive information that would normally be protected. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and represents a failure in proper access control mechanisms during system initialization. The device's operating system appears to lack sufficient protections during the boot sequence, creating an attack surface that persists for a brief but critical period.
The operational impact of this vulnerability extends beyond simple information disclosure, as the leaked credentials and configuration data can provide attackers with comprehensive insights into the device's operational environment. Attackers who successfully exploit this vulnerability gain access to administrative credentials that can be used to modify device settings, redirect traffic, or establish persistent access points within the network. The disclosure of configuration information may reveal network topology details, IP address ranges, and service configurations that could facilitate further attacks. This vulnerability directly aligns with ATT&CK technique T1082 "System Information Discovery" and T1566 "Phishing for Information" as it enables attackers to gather system information and credentials without requiring physical access or complex attack vectors. The exposure of sensitive data during the boot process creates a window of opportunity that can be exploited by automated scanning tools to identify and compromise multiple devices simultaneously.
Mitigation strategies for this vulnerability should focus on both immediate operational responses and long-term architectural improvements. Network administrators should implement network segmentation to limit access to these devices and consider deploying intrusion detection systems that can monitor for unusual boot process activity. The device firmware should be updated to the latest available version that addresses the specific boot information disclosure issue, as Cisco has released patches to resolve this vulnerability. Organizations should also consider implementing network access control measures that restrict which systems can communicate with the device during its vulnerable boot window. Additional security measures include disabling unnecessary services during the boot process, implementing strong authentication mechanisms, and monitoring network traffic for suspicious patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper access control implementation during system initialization phases and highlights the need for security by design principles in network infrastructure devices.