How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, 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.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

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.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

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. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

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.

Q: How do we prioritize remediation without burning out the team?

Use a 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 so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

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.

346,508

Total vulnerabilities in the database

CVE-2020-1617 — juniper / junos

Improper Initialization

This issue occurs on Juniper Networks Junos OS devices which do not support Advanced Forwarding Interface (AFI) / Advanced Forwarding Toolkit (AFT). Devices using AFI and AFT are not exploitable to this issue. An improper initialization of memory in the packet forwarding architecture in Juniper Networks Junos OS non-AFI/AFT platforms which may lead to a Denial of Service (DoS) vulnerability being exploited when a genuine packet is received and inspected by non-AFT/AFI sFlow and when the device is also configured with firewall policers. This first genuine packet received and inspected by sampled flow (sFlow) through a specific firewall policer will cause the device to reboot. After the reboot has completed, if the device receives and sFlow inspects another genuine packet seen through a specific firewall policer, the device will generate a core file and reboot. Continued inspection of these genuine packets will create an extended Denial of Service (DoS) condition. Depending on the method for service restoration, e.g. hard boot or soft reboot, a core file may or may not be generated the next time the packet is received and inspected by sFlow. This issue affects: Juniper Networks Junos OS 17.4 versions prior to 17.4R2-S9, 17.4R3 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.1 versions prior to 18.1R3-S9 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.2X75 versions prior to 18.2X75-D12, 18.2X75-D30 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.2 versions prior to 18.2R3 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.3 versions prior to 18.3R3 on PTX1000 and PTX10000 Series, QFX10000 Series. This issue is not applicable to Junos OS versions before 17.4R1. This issue is not applicable to Junos OS Evolved or Junos OS with Advanced Forwarding Toolkit (AFT) forwarding implementations which use a different implementation of sFlow. The following example information is unrelated to this issue and is provided solely to assist you with determining if you have AFT or not. Example: A Junos OS device which supports the use of EVPN signaled VPWS with Flexible Cross Connect uses the AFT implementation. Since this configuration requires support and use of the AFT implementation to support this configuration, the device is not vulnerable to this issue as the sFlow implementation is different using the AFT architecture. For further details about AFT visit the AFI / AFT are in the links below. If you are uncertain if you use the AFI/AFT implementation or not, there are configuration examples in the links below which you may use to determine if you are vulnerable to this issue or not. If the commands work, you are. If not, you are not. You may also use the Feature Explorer to determine if AFI/AFT is supported or not. If you are still uncertain, please contact your support resources.

Published: Apr 8, 2020
Updated: Nov 9, 2025
CVE: CVE-2020-1617
Severity: High
Exploit:

CVSS v3:

Severity: High
Score: 7.5
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2:

Severity: High
Score: 7.8
AV:N/AC:L/Au:N/C:N/I:N/A:C

CWEs:

CWE-665

Affected Software
References

Software	From	Fixed in
juniper / junos	17.4-r1	17.4-r1.x
juniper / junos	17.4-r2	17.4-r2.x
juniper / junos	17.4-r2-s2	17.4-r2-s2.x
juniper / junos	17.4-r1-s1	17.4-r1-s1.x
juniper / junos	17.4	17.4.x
juniper / junos	17.4-r1-s2	17.4-r1-s2.x
juniper / junos	17.4-r2-s1	17.4-r2-s1.x
juniper / junos	17.4-r1-s7	17.4-r1-s7.x
juniper / junos	17.4-r1-s4	17.4-r1-s4.x
juniper / junos	17.4-r2-s3	17.4-r2-s3.x
juniper / junos	17.4-r2-s4	17.4-r2-s4.x
juniper / junos	17.4-r1-s6	17.4-r1-s6.x
juniper / junos	17.4-r2-s5	17.4-r2-s5.x
juniper / junos	17.4-r2-s6	17.4-r2-s6.x
juniper / junos	17.4-r2-s7	17.4-r2-s7.x
juniper / junos	17.4-r1-s5	17.4-r1-s5.x
juniper / junos	17.4-r2-s8	17.4-r2-s8.x
juniper / junos	18.1-r3-s8	18.1-r3-s8.x
juniper / junos	18.1-r3-s1	18.1-r3-s1.x
juniper / junos	18.1-r3-s6	18.1-r3-s6.x
juniper / junos	18.1-r3-s7	18.1-r3-s7.x
juniper / junos	18.1-r2-s2	18.1-r2-s2.x
juniper / junos	18.1-r3-s4	18.1-r3-s4.x
juniper / junos	18.1-r3-s3	18.1-r3-s3.x
juniper / junos	18.1-r3-s2	18.1-r3-s2.x
juniper / junos	18.1	18.1.x
juniper / junos	18.1-r2-s1	18.1-r2-s1.x
juniper / junos	18.1-r2-s4	18.1-r2-s4.x
juniper / junos	18.1-r3	18.1-r3.x
juniper / junos	18.1-r2	18.1-r2.x
juniper / junos	18.2	18.2.x
juniper / junos	18.2-r2-s1	18.2-r2-s1.x
juniper / junos	18.2-r2-s2	18.2-r2-s2.x
juniper / junos	18.2-r1-s3	18.2-r1-s3.x
juniper / junos	18.2-r2-s5	18.2-r2-s5.x
juniper / junos	18.2-r2-s6	18.2-r2-s6.x
juniper / junos	18.2-r2-s3	18.2-r2-s3.x
juniper / junos	18.2-r2-s4	18.2-r2-s4.x
juniper / junos	18.2-r1-s5	18.2-r1-s5.x
juniper / junos	18.2-r1	18.2-r1.x
juniper / junos	18.2x75	18.2x75.x
juniper / junos	18.2x75-d10	18.2x75-d10.x
juniper / junos	18.3-r1-s2	18.3-r1-s2.x
juniper / junos	18.3	18.3.x
juniper / junos	18.3-r1-s1	18.3-r1-s1.x
juniper / junos	18.3-r1-s5	18.3-r1-s5.x
juniper / junos	18.3-r2-s1	18.3-r2-s1.x
juniper / junos	18.3-r2-s2	18.3-r2-s2.x
juniper / junos	18.3-r2	18.3-r2.x
juniper / junos	18.3-r1	18.3-r1.x
juniper / junos	18.3-r1-s3	18.3-r1-s3.x

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

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.