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.
| Software | From | Fixed in |
|---|---|---|
| juniper / junos | 15.1-f1 | 15.1-f1.x |
| juniper / junos | 15.1-f2-s3 | 15.1-f2-s3.x |
| juniper / junos | 15.1-r3 | 15.1-r3.x |
| juniper / junos | 15.1-f2-s2 | 15.1-f2-s2.x |
| juniper / junos | 15.1-f4 | 15.1-f4.x |
| juniper / junos | 15.1-r4 | 15.1-r4.x |
| juniper / junos | 15.1-f2-s4 | 15.1-f2-s4.x |
| juniper / junos | 15.1-f6 | 15.1-f6.x |
| juniper / junos | 15.1-f2 | 15.1-f2.x |
| juniper / junos | 15.1-a1 | 15.1-a1.x |
| juniper / junos | 15.1-f3 | 15.1-f3.x |
| juniper / junos | 15.1-r2 | 15.1-r2.x |
| juniper / junos | 15.1-r1 | 15.1-r1.x |
| juniper / junos | 15.1-f2-s1 | 15.1-f2-s1.x |
| juniper / junos | 15.1-f5 | 15.1-f5.x |
| juniper / junos | 15.1 | 15.1.x |
| juniper / junos | 15.1x53-d10 | 15.1x53-d10.x |
| juniper / junos | 15.1x53-d40 | 15.1x53-d40.x |
| juniper / junos | 15.1x53-d62 | 15.1x53-d62.x |
| juniper / junos | 15.1x53-d20 | 15.1x53-d20.x |
| juniper / junos | 15.1x53-d30 | 15.1x53-d30.x |
| juniper / junos | 15.1x53-d33 | 15.1x53-d33.x |
| juniper / junos | 15.1x53-d63 | 15.1x53-d63.x |
| juniper / junos | 15.1x53-d32 | 15.1x53-d32.x |
| juniper / junos | 15.1x53-d57 | 15.1x53-d57.x |
| juniper / junos | 15.1x53-d34 | 15.1x53-d34.x |
| juniper / junos | 15.1x53-d64 | 15.1x53-d64.x |
| juniper / junos | 15.1x53-d210 | 15.1x53-d210.x |
| juniper / junos | 15.1x53-d21 | 15.1x53-d21.x |
| juniper / junos | 15.1x53-d60 | 15.1x53-d60.x |
| juniper / junos | 15.1x53-d45 | 15.1x53-d45.x |
| juniper / junos | 15.1x53-d61 | 15.1x53-d61.x |
| juniper / junos | 15.1x53-d230 | 15.1x53-d230.x |
| juniper / junos | 15.1x53-d50 | 15.1x53-d50.x |
| juniper / junos | 15.1x53-d51 | 15.1x53-d51.x |
| juniper / junos | 15.1x53-d52 | 15.1x53-d52.x |
| juniper / junos | 15.1x53-d55 | 15.1x53-d55.x |
| juniper / junos | 15.1x53-d65 | 15.1x53-d65.x |
| juniper / junos | 15.1x53-d231 | 15.1x53-d231.x |
| juniper / junos | 15.1x53-d58 | 15.1x53-d58.x |
| juniper / junos | 15.1x53-d66 | 15.1x53-d66.x |
| juniper / junos | 15.1x53-d232 | 15.1x53-d232.x |
| juniper / junos | 15.1x53-d233 | 15.1x53-d233.x |
| juniper / junos | 15.1x53-d59 | 15.1x53-d59.x |
| juniper / junos | 15.1x53-d67 | 15.1x53-d67.x |
| juniper / junos | 15.1x53-d68 | 15.1x53-d68.x |
| juniper / junos | 15.1x53 | 15.1x53.x |
| juniper / junos | 16.1-r1 | 16.1-r1.x |
| juniper / junos | 16.1-r4 | 16.1-r4.x |
| juniper / junos | 16.1-r3 | 16.1-r3.x |
| juniper / junos | 16.1-r5 | 16.1-r5.x |
| juniper / junos | 16.1-r2 | 16.1-r2.x |
| juniper / junos | 16.1-r6 | 16.1-r6.x |
| juniper / junos | 16.1-r7 | 16.1-r7.x |
| juniper / junos | 16.1 | 16.1.x |
| juniper / junos | 16.2-r2 | 16.2-r2.x |
| juniper / junos | 16.2-r1 | 16.2-r1.x |
| juniper / junos | 16.2-r2-s7 | 16.2-r2-s7.x |
| juniper / junos | 16.2-r2-s8 | 16.2-r2-s8.x |
| juniper / junos | 16.2 | 16.2.x |
| juniper / junos | 17.1-r1 | 17.1-r1.x |
| juniper / junos | 17.1-r2 | 17.1-r2.x |
| juniper / junos | 17.1 | 17.1.x |
| juniper / junos | 17.1-r2-s10 | 17.1-r2-s10.x |
| juniper / junos | 17.2-r1 | 17.2-r1.x |
| juniper / junos | 17.2-r1-s7 | 17.2-r1-s7.x |
| juniper / junos | 17.2 | 17.2.x |
| juniper / junos | 17.3-r1 | 17.3-r1.x |
| juniper / junos | 17.3 | 17.3.x |
| juniper / junos | 17.4-r1 | 17.4-r1.x |
| juniper / junos | 17.4 | 17.4.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.