CVE-2020-1617: This issue occurs on Juniper Networks Junos OS devices which do not support Advanced Forwarding Interface (AFI) / Advanced Forwarding Toolkit (AFT).

This issue occurs on Juniper Networks Junos OS devices which do not support Advanced Forwarding Interface (AFI) / Advanced Forwarding Toolkit (AFT).

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

Description from the National Vulnerability Database, published by sirt@juniper.net

What it means for a small business

Junos OS is network equipment or remote-access software: the box between your office and the internet. These are a favorite target because breaking one opens the whole office.

If an IT provider set it up, ask them to confirm the firmware version and the date it was updated. If nobody looks after it, that's the bigger problem.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 1.6%, higher than 75% of CVEs. That’s above average: worth scheduling this week. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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