CVE-2024-47489: An Improper Handling of Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of the Juniper Networks Junos OS Evolved on ACX Series device

An Improper Handling of Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of the Juniper Networks Junos OS Evolved on ACX Series device

An Improper Handling of Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of the Juniper Networks Junos OS Evolved on ACX Series devices allows an unauthenticated, network based attacker sending specific transit protocol traffic to cause a partial Denial of Service (DoS) to downstream devices. Receipt of specific transit protocol packets is incorrectly processed by the Routing Engine (RE), filling up the DDoS protection queue which is shared between routing protocols. This influx of transit protocol packets causes DDoS protection violations, resulting in protocol flaps which can affect connectivity to networking devices. This issue affects both IPv4 and IPv6. This issue does not require any specific routing protocol to be configured or enabled. The following commands can be used to monitor the DDoS protection queue: labuser@re0> show evo-pfemand host pkt-stats labuser@re0> show host-path ddos all-policers This issue affects Junos OS Evolved: * All versions before 21.4R3-S8-EVO, * from 22.2 before 22.2R3-S4-EVO, * from 22.3 before 22.3R3-S4-EVO, * from 22.4 before 22.4R3-S3-EVO, * from 23.2 before 23.2R2-EVO, * fro

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

What it means for a small business

Junos OS Evolved 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 0.66%, higher than 51% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 31, 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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