CVE-2019-3914 in Fios Quantum Gateway G1100
Summary
by MITRE
Remote command injection vulnerability in Verizon Fios Quantum Gateway (G1100) firmware version 02.01.00.05 allows a remote, authenticated attacker to execute arbitrary commands on the target device by adding an access control rule for a network object with a crafted hostname.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/29/2023
The CVE-2019-3914 vulnerability represents a critical remote command injection flaw discovered in the Verizon Fios Quantum Gateway model G1100 firmware version 02.01.00.05. This vulnerability resides within the device's web-based administration interface and specifically targets the handling of network object hostnames when creating access control rules. The flaw allows an authenticated attacker to inject malicious commands that are subsequently executed with root privileges on the underlying Linux-based system. The vulnerability stems from insufficient input validation and sanitization within the firewall configuration processing logic, creating a path for arbitrary code execution that bypasses normal authentication mechanisms and operates at the highest privilege level available on the device.
The technical exploitation of this vulnerability requires an attacker to possess valid administrative credentials for the gateway device, which typically includes a username and password combination. Once authenticated, the attacker can navigate to the access control rules section and create a new rule specifying a network object with a crafted hostname containing malicious command injection sequences. The device fails to properly escape or validate special characters in the hostname field, allowing operators such as semicolons, ampersands, or backticks to be interpreted as command separators or execution operators. This injection occurs during the processing of the hostname parameter within the firewall rule creation workflow, where the system directly incorporates user-supplied input into system commands without adequate sanitization. The vulnerability aligns with CWE-77 and CWE-94 categories, representing command injection flaws that enable arbitrary code execution through improper input handling. According to ATT&CK framework, this vulnerability maps to T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as the attacker can leverage the authenticated session to execute commands with root privileges.
The operational impact of CVE-2019-3914 extends beyond simple remote code execution, as it provides attackers with complete control over the affected gateway device and potentially the entire local network it manages. The gateway serves as a primary network gateway and firewall device for residential customers, meaning successful exploitation could allow attackers to bypass network security controls, monitor traffic, redirect connections, or establish persistent access points. The vulnerability's remote nature means attackers do not require physical access to the device, and the authenticated requirement makes it particularly dangerous as it can be exploited through social engineering or credential compromise attacks. Network administrators and security professionals have documented cases where similar vulnerabilities have been exploited to create backdoors, establish command and control channels, or facilitate lateral movement within home networks. The device's role as a primary internet gateway makes it a prime target for attackers seeking to maintain persistent access to residential networks while avoiding detection by standard network monitoring tools.
Mitigation strategies for CVE-2019-3914 should focus on both immediate remediation and long-term security improvements. The primary recommendation involves updating the firmware to the latest version provided by Verizon, which includes patches addressing the command injection vulnerability in the hostname handling logic. Network administrators should also implement network segmentation and access controls to limit the exposure of gateway devices, particularly by placing them in isolated network segments with restricted access. Regular monitoring of the device's configuration and access logs should be implemented to detect unauthorized rule modifications or suspicious administrative activities. The vulnerability demonstrates the importance of input validation and proper sanitization of user-supplied data, which should be implemented across all network device management interfaces. Organizations should consider implementing network access control lists that restrict administrative access to gateway devices to specific trusted IP addresses and require multi-factor authentication. Additionally, security awareness training for users should emphasize the importance of changing default credentials and maintaining strong authentication practices to prevent unauthorized access to network management interfaces. The vulnerability serves as a reminder of the critical need for proper security testing and validation of network device management interfaces to prevent command injection vulnerabilities that could provide attackers with complete system compromise capabilities.