A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause a Denial of Service (DoS).
PTX3000, PTX5000, QFX10000, PTX1000, PTX10002, and PTX10004, PTX10008 and PTX10016 with LC110x FPCs do not support certain flow-routes. Once a flow-route is received over an established BGP session and an attempt is made to install the resulting filter into the PFE, FPC heap memory is leaked. The FPC heap memory can be monitored using the CLI command "show chassis fpc".
The following syslog messages can be observed if the respective filter derived from a flow-route cannot be installed.
expr_dfw_sfm_range_add:661 SFM packet-length Unable to get a sfm entry for updating the hw expr_dfw_hw_sfm_add:750 Unable to add the filter secondarymatch to the hardware expr_dfw_base_hw_add:52 Failed to add h/w sfm data. expr_dfw_base_hw_create:114 Failed to add h/w data. expr_dfw_base_pfe_inst_create:241 Failed to create base inst for sfilter 0 on PFE 0 for flowspec_default_inet expr_dfw_flt_inst_change:1368 Failed to create flowspec_default_inet on PFE 0 expr_dfw_hw_pgm_fnum:465 dfw_pfe_inst_old not found for pfe_index 0! expr_dfw_bp_pgm_flt_num:548 Failed to pgm bind-point in hw: generic failure expr_dfw_bp_topo_handler:1102 Failed to program fnum. expr_dfw_entry_process_change:679 Failed to change instance for filter flowspec_default_inet. This issue affects Juniper Networks Junos OS:
on PTX1000, PTX10002, and PTX10004, PTX10008 and PTX10016 with LC110x FPCs:
on PTX3000, PTX5000, QFX10000:
| Software | From | Fixed in |
|---|---|---|
| juniper / junos | - | 20.4 |
| juniper / junos | 20.4-r3-s4 | 20.4-r3-s4.x |
| juniper / junos | 20.4-r1 | 20.4-r1.x |
| juniper / junos | 20.4-r1-s1 | 20.4-r1-s1.x |
| juniper / junos | 20.4-r2 | 20.4-r2.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-r3-s1 | 20.4-r3-s1.x |
| juniper / junos | 20.4-r2-s2 | 20.4-r2-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-s3 | 20.4-r3-s3.x |
| juniper / junos | 21.1 | 21.1.x |
| juniper / junos | 21.1-r3-s1 | 21.1-r3-s1.x |
| juniper / junos | 21.1-r2 | 21.1-r2.x |
| juniper / junos | 21.1-r2-s2 | 21.1-r2-s2.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-r1-s1 | 21.1-r1-s1.x |
| juniper / junos | 21.1-r1 | 21.1-r1.x |
| juniper / junos | 21.1-r3-s2 | 21.1-r3-s2.x |
| juniper / junos | 21.1-r3-s3 | 21.1-r3-s3.x |
| juniper / junos | 21.2-r3-s1 | 21.2-r3-s1.x |
| juniper / junos | 21.2-r1 | 21.2-r1.x |
| juniper / junos | 21.2-r1-s1 | 21.2-r1-s1.x |
| juniper / junos | 21.2 | 21.2.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-s2 | 21.2-r2-s2.x |
| juniper / junos | 21.2-r2 | 21.2-r2.x |
| juniper / junos | 21.2-r3 | 21.2-r3.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 | 21.3.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 | 21.3-r1 | 21.3-r1.x |
| juniper / junos | 21.3-r2 | 21.3-r2.x |
| juniper / junos | 21.4-r1-s1 | 21.4-r1-s1.x |
| juniper / junos | 21.4-r1-s2 | 21.4-r1-s2.x |
| juniper / junos | 21.4-r2 | 21.4-r2.x |
| juniper / junos | 21.4-r2-s1 | 21.4-r2-s1.x |
| juniper / junos | 21.4 | 21.4.x |
| juniper / junos | 21.4-r1 | 21.4-r1.x |
| juniper / junos | 22.1-r1 | 22.1-r1.x |
| juniper / junos | 22.1-r1-s1 | 22.1-r1-s1.x |
| juniper / junos | 20.4-r3-s5 | 20.4-r3-s5.x |
| juniper / junos | 20.4-r3-s7 | 20.4-r3-s7.x |
| juniper / junos | 20.4-r3-s6 | 20.4-r3-s6.x |
| juniper / junos | 21.1-r3-s5 | 21.1-r3-s5.x |
| juniper / junos | 21.1-r3-s4 | 21.1-r3-s4.x |
| juniper / junos | 21.2-r3-s2 | 21.2-r3-s2.x |
| juniper / junos | 21.2-r3-s3 | 21.2-r3-s3.x |
| juniper / junos | 21.2-r3-s4 | 21.2-r3-s4.x |
| juniper / junos | 21.2-r3-s5 | 21.2-r3-s5.x |
| juniper / junos | 21.3-r3 | 21.3-r3.x |
| juniper / junos | 21.3-r3-s1 | 21.3-r3-s1.x |
| juniper / junos | 21.3-r3-s3 | 21.3-r3-s3.x |
| juniper / junos | 21.3-r3-s4 | 21.3-r3-s4.x |
| juniper / junos | 21.3-r3-s2 | 21.3-r3-s2.x |
| juniper / junos | 21.4-r3 | 21.4-r3.x |
| juniper / junos | 21.4-r2-s2 | 21.4-r2-s2.x |
| juniper / junos | 21.4-r3-s3 | 21.4-r3-s3.x |
| juniper / junos | 21.4-r3-s2 | 21.4-r3-s2.x |
| juniper / junos | 21.4-r3-s1 | 21.4-r3-s1.x |
| juniper / junos | 22.1-r3-s1 | 22.1-r3-s1.x |
| juniper / junos | 22.1-r3 | 22.1-r3.x |
| juniper / junos | 22.1-r3-s2 | 22.1-r3-s2.x |
| juniper / junos | 22.1-r1-s2 | 22.1-r1-s2.x |
| juniper / junos | 22.1-r2-s2 | 22.1-r2-s2.x |
| juniper / junos | 22.1-r2 | 22.1-r2.x |
| juniper / junos | 22.1-r2-s1 | 22.1-r2-s1.x |
| juniper / junos | 22.2-r1 | 22.2-r1.x |
| juniper / junos | 22.2-r1-s1 | 22.2-r1-s1.x |
| juniper / junos | 22.2-r2 | 22.2-r2.x |
| juniper / junos | 22.2-r2-s2 | 22.2-r2-s2.x |
| juniper / junos | 22.2-r3 | 22.2-r3.x |
| juniper / junos | 22.2-r1-s2 | 22.2-r1-s2.x |
| juniper / junos | 22.2-r2-s1 | 22.2-r2-s1.x |
| juniper / junos | 22.3-r1-s2 | 22.3-r1-s2.x |
| juniper / junos | 22.3-r2 | 22.3-r2.x |
| juniper / junos | 22.3-r1 | 22.3-r1.x |
| juniper / junos | 22.3-r1-s1 | 22.3-r1-s1.x |
| juniper / junos | 22.3-r2-s1 | 22.3-r2-s1.x |
| juniper / junos | 22.4-r1 | 22.4-r1.x |
| juniper / junos | 22.4-r1-s1 | 22.4-r1-s1.x |
| juniper / junos | 22.4-r1-s2 | 22.4-r1-s2.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.