CVE-2020-20184 in GateOne
Summary
by MITRE • 12/15/2020
GateOne allows remote attackers to execute arbitrary commands via shell metacharacters in the port field when attempting an SSH connection.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/17/2020
The vulnerability identified as CVE-2020-20184 resides within GateOne, a web-based terminal emulator and SSH client that enables remote access to systems through browser interfaces. This security flaw represents a critical command injection vulnerability that allows remote attackers to execute arbitrary system commands through manipulation of shell metacharacters within the port field during SSH connection attempts. The vulnerability stems from insufficient input validation and sanitization mechanisms within the application's SSH connection handling process, specifically targeting how the application processes the port parameter when establishing secure shell connections. The flaw affects GateOne versions prior to 1.2.3, making it a significant concern for organizations that rely on this terminal emulator for remote system administration and access management.
The technical implementation of this vulnerability exploits the application's failure to properly sanitize user-supplied input before incorporating it into shell command executions. When users attempt to establish SSH connections through GateOne, they provide connection parameters including hostname and port information. The application constructs shell commands using these parameters without adequate validation, allowing attackers to inject shell metacharacters such as semicolons, pipes, or other command separators into the port field. This injection occurs because the application treats the port parameter as a literal string value rather than properly escaping or validating it against shell command syntax. The vulnerability specifically targets the command construction phase where the application builds system calls to initiate SSH connections, creating an environment where malicious input can be interpreted as additional shell commands rather than simple port specifications.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with potential access to underlying system resources and capabilities. Remote attackers can leverage this vulnerability to execute arbitrary commands with the privileges of the GateOne service account, potentially leading to full system compromise if the service operates with elevated permissions. The vulnerability enables attackers to perform actions such as reading sensitive files, executing system binaries, establishing reverse shells, or modifying system configurations. Given that GateOne typically operates in environments requiring secure remote access, this vulnerability could be exploited to gain unauthorized access to critical infrastructure, potentially leading to data breaches, system corruption, or further lateral movement within network environments. The remote nature of the exploit eliminates the need for physical access or local system compromise, making it particularly dangerous in enterprise environments where remote access is commonly utilized.
Organizations should implement immediate mitigations including updating to GateOne version 1.2.3 or later, which includes proper input sanitization and validation mechanisms. The fix addresses the vulnerability by implementing proper shell escaping techniques and input validation that prevents metacharacter interpretation during command construction. Additional protective measures include network segmentation to limit access to GateOne services, implementing strict access controls and authentication mechanisms, and monitoring for suspicious connection attempts that may indicate exploitation attempts. Security professionals should also consider deploying intrusion detection systems capable of identifying shell command injection patterns and implementing web application firewalls to filter malicious input. The vulnerability aligns with CWE-77 and CWE-94 categories related to command injection and code injection respectively, and represents a technique commonly classified under ATT&CK tactic TA0002 (Execution) and technique T1059.001 (Command and Scripting Interpreter) in the MITRE ATT&CK framework, highlighting the need for comprehensive defensive strategies that address both application-level and network-level protections.