A sustained sequence of different types of normal transit traffic can trigger a high CPU consumption denial of service condition in the Junos OS register and schedule software interrupt handler subsystem when a specific command is issued to the device. This affects one or more threads and conversely one or more running processes running on the system. Once this occurs, the high CPU event(s) affects either or both the forwarding and control plane. As a result of this condition the device can become inaccessible in either or both the control and forwarding plane and stops forwarding traffic until the device is rebooted. The issue will reoccur after reboot upon receiving further transit traffic. Score: 5.7 MEDIUM (CVSS:3.0/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) For network designs utilizing layer 3 forwarding agents or other ARP through layer 3 technologies, the score is slightly higher. Score: 6.5 MEDIUM (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) If the following entry exists in the RE message logs then this may indicate the issue is present. This entry may or may not appear when this issue occurs. /kernel: Expensive timeout(9) function: Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D50; 12.3X48 versions prior to 12.3X48-D30; 12.3R versions prior to 12.3R12-S7; 14.1 versions prior to 14.1R8-S4, 14.1R9; 14.1X53 versions prior to 14.1X53-D30, 14.1X53-D34; 14.2 versions prior to 14.2R8; 15.1 versions prior to 15.1F6, 15.1R3; 15.1X49 versions prior to 15.1X49-D40; 15.1X53 versions prior to 15.1X53-D31, 15.1X53-D33, 15.1X53-D60. No other Juniper Networks products or platforms are affected by this issue.
| Software | From | Fixed in |
|---|---|---|
| juniper / junos | 12.1x46-d30 | 12.1x46-d30.x |
| juniper / junos | 12.1x46-d45 | 12.1x46-d45.x |
| juniper / junos | 12.1x46-d25 | 12.1x46-d25.x |
| juniper / junos | 12.1x46 | 12.1x46.x |
| juniper / junos | 12.1x46-d35 | 12.1x46-d35.x |
| juniper / junos | 12.1x46-d20 | 12.1x46-d20.x |
| juniper / junos | 12.1x46-d40 | 12.1x46-d40.x |
| juniper / junos | 12.1x46-d15 | 12.1x46-d15.x |
| juniper / junos | 12.1x46-d10 | 12.1x46-d10.x |
| juniper / junos | 12.3x48-d10 | 12.3x48-d10.x |
| juniper / junos | 12.3x48-d15 | 12.3x48-d15.x |
| juniper / junos | 12.3x48 | 12.3x48.x |
| juniper / junos | 12.3x48-d25 | 12.3x48-d25.x |
| juniper / junos | 12.3x48-d20 | 12.3x48-d20.x |
| juniper / junos | 12.3-r11 | 12.3-r11.x |
| juniper / junos | 12.3-r2 | 12.3-r2.x |
| juniper / junos | 12.3-r9 | 12.3-r9.x |
| juniper / junos | 12.3-r4 | 12.3-r4.x |
| juniper / junos | 12.3-r1 | 12.3-r1.x |
| juniper / junos | 12.3-r7 | 12.3-r7.x |
| juniper / junos | 12.3-r6 | 12.3-r6.x |
| juniper / junos | 12.3-r12 | 12.3-r12.x |
| juniper / junos | 12.3-r5 | 12.3-r5.x |
| juniper / junos | 12.3-r3 | 12.3-r3.x |
| juniper / junos | 12.3-r8 | 12.3-r8.x |
| juniper / junos | 14.1-r1 | 14.1-r1.x |
| juniper / junos | 14.1-r4 | 14.1-r4.x |
| juniper / junos | 14.1 | 14.1.x |
| juniper / junos | 14.1-r3 | 14.1-r3.x |
| juniper / junos | 14.1-r9 | 14.1-r9.x |
| juniper / junos | 14.1-r7 | 14.1-r7.x |
| juniper / junos | 14.1-r6 | 14.1-r6.x |
| juniper / junos | 14.1-r2 | 14.1-r2.x |
| juniper / junos | 14.1-r5 | 14.1-r5.x |
| juniper / junos | 14.1x53-d15 | 14.1x53-d15.x |
| juniper / junos | 14.1x53-d10 | 14.1x53-d10.x |
| juniper / junos | 14.1x53-d25 | 14.1x53-d25.x |
| juniper / junos | 14.1x53-d27 | 14.1x53-d27.x |
| juniper / junos | 14.1x53-d16 | 14.1x53-d16.x |
| juniper / junos | 14.1x53 | 14.1x53.x |
| juniper / junos | 14.1x53-d26 | 14.1x53-d26.x |
| juniper / junos | 14.1x53-d34 | 14.1x53-d34.x |
| juniper / junos | 14.2-r1 | 14.2-r1.x |
| juniper / junos | 14.2-r2 | 14.2-r2.x |
| juniper / junos | 14.2-r3 | 14.2-r3.x |
| juniper / junos | 14.2-r6 | 14.2-r6.x |
| juniper / junos | 14.2 | 14.2.x |
| juniper / junos | 14.2-r7 | 14.2-r7.x |
| juniper / junos | 14.2-r4 | 14.2-r4.x |
| juniper / junos | 14.2-r5 | 14.2-r5.x |
| 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-f2-s4 | 15.1-f2-s4.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-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 | 15.1x49-d30 | 15.1x49-d30.x |
| juniper / junos | 15.1x49 | 15.1x49.x |
| juniper / junos | 15.1x49-d35 | 15.1x49-d35.x |
| juniper / junos | 15.1x49-d20 | 15.1x49-d20.x |
| juniper / junos | 15.1x49-d10 | 15.1x49-d10.x |
| juniper / junos | 15.1x53-d10 | 15.1x53-d10.x |
| juniper / junos | 15.1x53-d20 | 15.1x53-d20.x |
| juniper / junos | 15.1x53-d30 | 15.1x53-d30.x |
| juniper / junos | 15.1x53 | 15.1x53.x |
| juniper / junos | 15.1x53-d33 | 15.1x53-d33.x |
| juniper / junos | 15.1x53-d25 | 15.1x53-d25.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 |
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.