CVE-2018-0099 in D9800 Network Transport Receiver
Summary
by MITRE
A vulnerability in the web management GUI of the Cisco D9800 Network Transport Receiver could allow an authenticated, remote attacker to perform a command injection attack. The vulnerability is due to insufficient input validation of GUI command arguments. An attacker could exploit this vulnerability by injecting crafted arguments into a vulnerable GUI command. An exploit could allow the attacker to execute commands on the underlying BusyBox operating system. These commands are run at the privilege level of the authenticated user. The attacker needs valid device credentials for this attack. Cisco Bug IDs: CSCvg74691.
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Analysis
by VulDB Data Team • 02/01/2021
The vulnerability identified as CVE-2018-0099 resides within the web management graphical user interface of Cisco D9800 Network Transport Receiver devices, representing a critical security flaw that enables authenticated remote command injection attacks. This vulnerability stems from inadequate input validation mechanisms within the GUI command processing functionality, creating a pathway for malicious actors to manipulate system operations through carefully crafted inputs. The affected device operates on a BusyBox-based operating system environment where command execution occurs with the privileges of the authenticated user, potentially allowing attackers to gain unauthorized access to system resources and execute arbitrary code.
The technical exploitation of this vulnerability occurs through the injection of malicious arguments into GUI commands that lack proper sanitization or validation controls. When authenticated users interact with the web management interface, the system fails to adequately validate or sanitize the input parameters passed to underlying system commands, creating an environment where attacker-controlled data can be interpreted as executable commands. This flaw aligns with CWE-74, which describes improper neutralization of special elements used in a command, and represents a classic command injection vulnerability that can be leveraged for privilege escalation within the authenticated user context. The attack vector requires remote access through the web GUI interface, making it particularly dangerous as it can be executed from outside the local network perimeter.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the ability to manipulate system configurations, access sensitive data, and potentially establish persistent access to the affected device. Since commands execute with the privileges of the authenticated user, attackers who gain valid credentials can perform actions such as modifying system settings, accessing network configurations, or even installing malicious software on the device. The vulnerability's exploitation does not require administrative privileges beyond valid user authentication, making it particularly concerning for environments where user access controls may be insufficient. This weakness can be mapped to ATT&CK technique T1059.001, which covers command and scripting interpreter execution, and T1566, which addresses credential harvesting through social engineering or brute force attacks.
Mitigation strategies for CVE-2018-0099 should focus on implementing comprehensive input validation controls within the web management interface, including the deployment of proper parameter sanitization and validation mechanisms. Organizations should ensure that all user-supplied inputs undergo rigorous filtering and validation before being processed by underlying system commands. Cisco has released software updates to address this vulnerability, and administrators should immediately apply the relevant security patches to prevent exploitation. Network segmentation and access control measures should be implemented to limit the attack surface, while monitoring systems should be configured to detect unusual command execution patterns or unauthorized access attempts. Additionally, regular security assessments should be conducted to identify similar input validation weaknesses in other network management interfaces and applications. The vulnerability demonstrates the critical importance of validating all user inputs and implementing defense-in-depth strategies to protect network infrastructure devices from authenticated command injection attacks.