Junos OS: Specially crafted packets sent to port 111 on any interface triggers responses from the management interface

Summary

On Junos OS, rpcbind should only be listening to port 111 on the internal routing instance (IRI). External packets destined to port 111 should be dropped. Due to an information leak vulnerability, responses were being generated from the source address of the management interface (e.g. fxp0) thus disclosing internal addressing and existence of the management interface itself. A high rate of crafted packets destined to port 111 may also lead to a partial Denial of Service (DoS). Note: Systems with fxp0 disabled or unconfigured are not vulnerable to this issue. This issue only affects Junos OS releases based on FreeBSD 10 or higher (typically Junos OS 15.1+). Administrators can confirm whether systems are running a version of Junos OS based on FreeBSD 10 or higher by typing: user@junos> show version | match kernel JUNOS OS Kernel 64-bit [20181214.223829_fbsd-builder_stable_10] Affected releases are Juniper Networks Junos OS: 15.1 versions prior to 15.1F6-S12, 15.1R7-S4; 15.1X53 versions prior to 15.1X53-D236; 16.1 versions prior to 16.1R7-S1; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R1-S8; 17.3 versions prior to 17.3R2; 17.4 versions prior to 17.4R1-S1, 17.4R1-S7, 17.4R2. This issue does not affect Junos OS releases prior to 15.1.