Starting with Junos OS Release 16.1R3, the Junos Telemetry Interface supports Google gRPC remote procedure calls to provision sensors and to subscribe to and receive telemetry data. Configuration files used by gRPC were found to contain hardcoded credentials that could be used by the Junos Network Agent to perform unauthorized read of certain non-critical information (e.g. sensor data). Additionally, APIs exposed via the Juniper Extension Toolkit (JET) may be able to perform non-critical ‘set’ operations on the device. These APIs need the client to be authenticated for which the username/password can be used. Successful exploitation of this vulnerability can only occur if the Junos Network Agent package (Junos Telemetry Interface) is installed on the device. If the Junos Network Agent is not installed, then the gRPC interface required to leverage these credentials is unavailable and the system is not vulnerable to this issue. Affected releases are Juniper Networks Junos OS: 16.1 versions prior to 16.1R3-S10, 16.1R7-S4; 17.1 versions prior to 17.1R2-S10, 17.1R3; 17.2 versions prior to 17.2R1-S8, 17.2R3-S1; 17.3 versions prior to 17.3R3-S3; 17.4 versions prior to 17.4R1-S6, 17.4R2-S3; 18.1 versions prior to 18.1R2-S4, 18.1R3-S3; 18.2 versions prior to 18.2R1-S5, 18.2R2-S1; 18.2X75 versions prior to 18.2X75-D40; 18.3 versions prior to 18.3R1-S2, 18.3R1-S3. This issue does not affect Junos OS releases prior to 16.1.