An Improper Handling of Exceptional Conditions vulnerability on specific PTX Series devices, including the PTX1000, PTX3000 (NextGen), PTX5000, PTX10002-60C, PTX10008, and PTX10016 Series, in Juniper Networks Junos OS allows an unauthenticated MPLS-based attacker to cause a Denial of Service (DoS) by triggering the dcpfe process to crash and FPC to restart. On affected PTX Series devices, processing specific MPLS packets received on an interface with multiple units configured may cause FPC to restart unexpectedly. Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects PTX Series devices utilizing specific FPCs found on PTX1000, PTX3000 (NextGen), PTX5000, PTX10002-60C, PTX10008, and PTX10016 Series devices, only if multiple units are configured on the ingress interface, and at least one unit has 'family mpls' not configured. See the configuration sample below for more information. No other platforms are affected by this vulnerability. This issue affects: Juniper Networks Junos OS on PTX Series: All versions prior to 19.1R3-S9; 19.2 versions prior to 19.2R3-S6; 19.3 versions prior to 19.3R3-S6; 19.4 versions prior to 19.4R3-S8; 20.1 versions prior to 20.1R3-S4; 20.2 versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S4; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3-S2; 21.2 versions prior to 21.2R3-S1; 21.3 versions prior to 21.3R3; 21.4 versions prior to 21.4R2; 22.1 versions prior to 22.1R2.
| Software | From | Fixed in |
|---|---|---|
| juniper / junos | - | 19.1 |
| juniper / junos | 19.1-r1-s6 | 19.1-r1-s6.x |
| juniper / junos | 19.1-r3-s3 | 19.1-r3-s3.x |
| juniper / junos | 19.1-r1-s5 | 19.1-r1-s5.x |
| juniper / junos | 19.1-r3-s4 | 19.1-r3-s4.x |
| juniper / junos | 19.1-r2-s2 | 19.1-r2-s2.x |
| juniper / junos | 19.1-r1-s1 | 19.1-r1-s1.x |
| juniper / junos | 19.1-r1-s3 | 19.1-r1-s3.x |
| juniper / junos | 19.1-r1-s2 | 19.1-r1-s2.x |
| juniper / junos | 19.1-r1 | 19.1-r1.x |
| juniper / junos | 19.1 | 19.1.x |
| juniper / junos | 19.1-r2 | 19.1-r2.x |
| juniper / junos | 19.1-r1-s4 | 19.1-r1-s4.x |
| juniper / junos | 19.1-r2-s1 | 19.1-r2-s1.x |
| juniper / junos | 19.1-r3 | 19.1-r3.x |
| juniper / junos | 19.1-r3-s1 | 19.1-r3-s1.x |
| juniper / junos | 19.1-r3-s2 | 19.1-r3-s2.x |
| juniper / junos | 19.1-r3-s5 | 19.1-r3-s5.x |
| juniper / junos | 19.1-r3-s6 | 19.1-r3-s6.x |
| juniper / junos | 19.1-r3-s7 | 19.1-r3-s7.x |
| juniper / junos | 19.1-r2-s3 | 19.1-r2-s3.x |
| juniper / junos | 19.1-r3-s8 | 19.1-r3-s8.x |
| juniper / junos | 19.2-r1-s9 | 19.2-r1-s9.x |
| juniper / junos | 19.2-r3-s5 | 19.2-r3-s5.x |
| juniper / junos | 19.2-r1-s8 | 19.2-r1-s8.x |
| juniper / junos | 19.2-r1-s7 | 19.2-r1-s7.x |
| juniper / junos | 19.2-r3-s4 | 19.2-r3-s4.x |
| juniper / junos | 19.2-r3-s3 | 19.2-r3-s3.x |
| juniper / junos | 19.2-r3-s2 | 19.2-r3-s2.x |
| juniper / junos | 19.2-r2 | 19.2-r2.x |
| juniper / junos | 19.2-r3 | 19.2-r3.x |
| juniper / junos | 19.2-r1-s4 | 19.2-r1-s4.x |
| juniper / junos | 19.2-r1 | 19.2-r1.x |
| juniper / junos | 19.2 | 19.2.x |
| juniper / junos | 19.2-r1-s3 | 19.2-r1-s3.x |
| juniper / junos | 19.2-r1-s1 | 19.2-r1-s1.x |
| juniper / junos | 19.2-r1-s2 | 19.2-r1-s2.x |
| juniper / junos | 19.2-r1-s6 | 19.2-r1-s6.x |
| juniper / junos | 19.2-r3-s1 | 19.2-r3-s1.x |
| juniper / junos | 19.2-r2-s1 | 19.2-r2-s1.x |
| juniper / junos | 19.2-r1-s5 | 19.2-r1-s5.x |
| juniper / junos | 19.3-r3-s1 | 19.3-r3-s1.x |
| juniper / junos | 19.3 | 19.3.x |
| juniper / junos | 19.3-r1 | 19.3-r1.x |
| juniper / junos | 19.3-r2-s1 | 19.3-r2-s1.x |
| juniper / junos | 19.3-r1-s1 | 19.3-r1-s1.x |
| juniper / junos | 19.3-r2-s5 | 19.3-r2-s5.x |
| juniper / junos | 19.3-r3 | 19.3-r3.x |
| juniper / junos | 19.3-r2-s4 | 19.3-r2-s4.x |
| juniper / junos | 19.3-r2 | 19.3-r2.x |
| juniper / junos | 19.3-r2-s2 | 19.3-r2-s2.x |
| juniper / junos | 19.3-r2-s3 | 19.3-r2-s3.x |
| juniper / junos | 19.3-r3-s2 | 19.3-r3-s2.x |
| juniper / junos | 19.3-r3-s3 | 19.3-r3-s3.x |
| juniper / junos | 19.3-r3-s4 | 19.3-r3-s4.x |
| juniper / junos | 19.3-r2-s6 | 19.3-r2-s6.x |
| juniper / junos | 19.3-r3-s5 | 19.3-r3-s5.x |
| juniper / junos | 19.4-r2-s6 | 19.4-r2-s6.x |
| juniper / junos | 19.4-r3-s7 | 19.4-r3-s7.x |
| juniper / junos | 19.4 | 19.4.x |
| juniper / junos | 19.4-r2-s5 | 19.4-r2-s5.x |
| juniper / junos | 19.4-r3-s6 | 19.4-r3-s6.x |
| juniper / junos | 19.4-r2-s4 | 19.4-r2-s4.x |
| juniper / junos | 19.4-r3-s5 | 19.4-r3-s5.x |
| juniper / junos | 19.4-r1-s4 | 19.4-r1-s4.x |
| juniper / junos | 19.4-r2 | 19.4-r2.x |
| juniper / junos | 19.4-r2-s1 | 19.4-r2-s1.x |
| juniper / junos | 19.4-r1-s1 | 19.4-r1-s1.x |
| juniper / junos | 19.4-r3 | 19.4-r3.x |
| juniper / junos | 19.4-r1-s2 | 19.4-r1-s2.x |
| juniper / junos | 19.4-r1 | 19.4-r1.x |
| juniper / junos | 19.4-r3-s2 | 19.4-r3-s2.x |
| juniper / junos | 19.4-r3-s3 | 19.4-r3-s3.x |
| juniper / junos | 19.4-r3-s4 | 19.4-r3-s4.x |
| juniper / junos | 19.4-r2-s2 | 19.4-r2-s2.x |
| juniper / junos | 19.4-r3-s1 | 19.4-r3-s1.x |
| juniper / junos | 19.4-r2-s3 | 19.4-r2-s3.x |
| juniper / junos | 19.4-r1-s3 | 19.4-r1-s3.x |
| juniper / junos | 20.1-r1-s4 | 20.1-r1-s4.x |
| juniper / junos | 20.1-r3 | 20.1-r3.x |
| juniper / junos | 20.1-r2 | 20.1-r2.x |
| juniper / junos | 20.1-r2-s1 | 20.1-r2-s1.x |
| juniper / junos | 20.1-r1-s1 | 20.1-r1-s1.x |
| juniper / junos | 20.1-r1 | 20.1-r1.x |
| juniper / junos | 20.1-r1-s2 | 20.1-r1-s2.x |
| juniper / junos | 20.1-r1-s3 | 20.1-r1-s3.x |
| juniper / junos | 20.1-r2-s2 | 20.1-r2-s2.x |
| juniper / junos | 20.1-r3-s1 | 20.1-r3-s1.x |
| juniper / junos | 20.1-r3-s2 | 20.1-r3-s2.x |
| juniper / junos | 20.1-r3-s3 | 20.1-r3-s3.x |
| juniper / junos | 20.1 | 20.1.x |
| juniper / junos | 20.2 | 20.2.x |
| juniper / junos | 20.2-r3-s4 | 20.2-r3-s4.x |
| juniper / junos | 20.2-r3-s3 | 20.2-r3-s3.x |
| juniper / junos | 20.2-r3-s2 | 20.2-r3-s2.x |
| juniper / junos | 20.2-r1-s1 | 20.2-r1-s1.x |
| juniper / junos | 20.2-r1-s2 | 20.2-r1-s2.x |
| juniper / junos | 20.2-r1 | 20.2-r1.x |
| juniper / junos | 20.2-r2-s3 | 20.2-r2-s3.x |
| juniper / junos | 20.2-r2-s2 | 20.2-r2-s2.x |
| juniper / junos | 20.2-r3 | 20.2-r3.x |
| juniper / junos | 20.2-r3-s1 | 20.2-r3-s1.x |
| juniper / junos | 20.2-r1-s3 | 20.2-r1-s3.x |
| juniper / junos | 20.2-r2 | 20.2-r2.x |
| juniper / junos | 20.2-r2-s1 | 20.2-r2-s1.x |
| juniper / junos | 20.3-r1-s1 | 20.3-r1-s1.x |
| juniper / junos | 20.3-r1 | 20.3-r1.x |
| juniper / junos | 20.3-r2-s1 | 20.3-r2-s1.x |
| juniper / junos | 20.3-r2 | 20.3-r2.x |
| juniper / junos | 20.3-r3 | 20.3-r3.x |
| juniper / junos | 20.3-r3-s1 | 20.3-r3-s1.x |
| juniper / junos | 20.3-r1-s2 | 20.3-r1-s2.x |
| juniper / junos | 20.3-r3-s3 | 20.3-r3-s3.x |
| juniper / junos | 20.3 | 20.3.x |
| juniper / junos | 20.3-r3-s2 | 20.3-r3-s2.x |
| juniper / junos | 20.4 | 20.4.x |
| juniper / junos | 20.4-r3-s2 | 20.4-r3-s2.x |
| juniper / junos | 20.4-r3-s1 | 20.4-r3-s1.x |
| juniper / junos | 20.4-r2-s2 | 20.4-r2-s2.x |
| juniper / junos | 20.4-r2-s1 | 20.4-r2-s1.x |
| juniper / junos | 20.4-r3 | 20.4-r3.x |
| juniper / junos | 20.4-r1-s1 | 20.4-r1-s1.x |
| juniper / junos | 20.4-r1 | 20.4-r1.x |
| juniper / junos | 20.4-r2 | 20.4-r2.x |
| juniper / junos | 21.1-r1 | 21.1-r1.x |
| juniper / junos | 21.1-r1-s1 | 21.1-r1-s1.x |
| juniper / junos | 21.1-r3 | 21.1-r3.x |
| juniper / junos | 21.1-r2-s1 | 21.1-r2-s1.x |
| juniper / junos | 21.1-r3-s1 | 21.1-r3-s1.x |
| juniper / junos | 21.1 | 21.1.x |
| juniper / junos | 21.1-r2 | 21.1-r2.x |
| juniper / junos | 21.1-r2-s2 | 21.1-r2-s2.x |
| juniper / junos | 21.2-r1-s2 | 21.2-r1-s2.x |
| juniper / junos | 21.2-r2-s1 | 21.2-r2-s1.x |
| juniper / junos | 21.2-r2 | 21.2-r2.x |
| juniper / junos | 21.2-r2-s2 | 21.2-r2-s2.x |
| juniper / junos | 21.2-r3 | 21.2-r3.x |
| juniper / junos | 21.2 | 21.2.x |
| juniper / junos | 21.2-r1 | 21.2-r1.x |
| juniper / junos | 21.2-r1-s1 | 21.2-r1-s1.x |
| juniper / junos | 21.3-r1 | 21.3-r1.x |
| juniper / junos | 21.3-r2 | 21.3-r2.x |
| juniper / junos | 21.3-r1-s1 | 21.3-r1-s1.x |
| juniper / junos | 21.3-r1-s2 | 21.3-r1-s2.x |
| juniper / junos | 21.3-r2-s1 | 21.3-r2-s1.x |
| juniper / junos | 21.3-r2-s2 | 21.3-r2-s2.x |
| juniper / junos | 21.4-r1-s2 | 21.4-r1-s2.x |
| juniper / junos | 21.4-r1-s1 | 21.4-r1-s1.x |
| juniper / junos | 21.4-r1 | 21.4-r1.x |
| juniper / junos | 22.1-r1 | 22.1-r1.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.