Denial of Service Vulnerability in Juniper Networks Junos OS Routing Protocol Daemon

CVE-2025-21597

Summary

A vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved can be exploited by an unauthenticated BGP peer, enabling the attacker to trigger a Denial of Service (DoS). When certain configurations are in place—namely BGP rib-sharding and update-threading—a BGP peer can cause rpd to crash and restart through specific timing of peer flaps. This behavior persists, leading to continuous disruptions in service. The vulnerability affects both eBGP and iBGP implementations for IPv4 and IPv6, requiring at least one established BGP session from the remote attacker, and may impact users with or without logical systems enabled.

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