CVE-2013-4874 in Wireless Network Extender
Summary
by MITRE
The Uboot bootloader on the Verizon Wireless Network Extender SCS-26UC4 allows physically proximate attackers to obtain root access by connecting a crafted HDMI cable and using a sys session to modify the ramboot environment variable.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/16/2024
The vulnerability identified as CVE-2013-4874 represents a critical security flaw in the Uboot bootloader implementation of the Verizon Wireless Network Extender SCS-26UC4 device. This vulnerability exposes a fundamental weakness in the device's boot process and privilege management system, allowing attackers with physical proximity to escalate their privileges from standard user level to root access. The device operates as a wireless extender that connects to Verizon's network infrastructure, making it a potential target for attackers seeking to compromise cellular network connectivity and data transmission. The security implications extend beyond simple privilege escalation, as this vulnerability could enable attackers to gain complete control over the device's network operations and potentially use it as a foothold for broader network infiltration.
The technical mechanism behind this vulnerability involves the manipulation of the ramboot environment variable through a specially crafted HDMI connection. This attack vector demonstrates a significant flaw in the device's physical security model, where the bootloader does not properly validate or protect critical system variables from unauthorized modification. The ramboot environment variable typically contains essential boot parameters and system configuration data that, when modified by an attacker, can alter the device's boot process and grant elevated privileges. The requirement for physical proximity means that attackers must be within direct reach of the device, typically within a few feet, but this limitation does not mitigate the severity of the vulnerability given the potential for complete system compromise. This attack method aligns with the common security principle of insufficient physical security controls, where device designers fail to account for the threat of physical manipulation.
The operational impact of this vulnerability is substantial for both individual users and network operators. For end users, the compromise of the Network Extender could result in unauthorized access to their cellular network connection, potentially enabling man-in-the-middle attacks, data interception, or service disruption. Network operators face more severe implications as these devices serve as critical infrastructure points for cellular connectivity, and their compromise could affect service availability and data integrity across large geographic areas. The vulnerability creates a persistent threat that remains active as long as the device is operational and within physical reach of an attacker. This characteristic makes it particularly dangerous in environments where device security cannot be guaranteed, such as public spaces or shared facilities where unauthorized physical access is possible.
Security professionals should implement multiple layers of mitigation strategies to address this vulnerability effectively. The primary recommendation involves immediate firmware updates from Verizon to patch the bootloader implementation and prevent unauthorized modification of critical environment variables. Additionally, network administrators should consider implementing physical security measures such as device enclosures or tamper-evident seals to detect unauthorized access attempts. The vulnerability demonstrates the importance of proper access control mechanisms in embedded systems, aligning with common security frameworks that emphasize the need for robust privilege separation and secure boot processes. Organizations should also conduct regular security assessments of their network infrastructure devices to identify similar vulnerabilities that might exist in other embedded systems or network equipment. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the boot process and environment variable manipulation, while CWE classification would likely fall under weakness categories related to insufficient physical security controls and improper privilege management.