CVE-2023-44186

Name of the Vulnerable Software and Affected Versions Juniper Networks Junos OS versions prior to 20.4R3-S8 Juniper Networks Junos OS versions 21.1R1 and later Juniper Networks Junos OS versions prior to 21.2R3-S6 Juniper Networks Junos OS versions prior to 21.3R3-S5 Juniper Networks Junos OS versions prior to 21.4R3-S5 Juniper Networks Junos OS versions prior to 22.1R3-S4 Juniper Networks Junos OS versions prior to 22.2R3-S2 Juniper Networks Junos OS versions prior to 22.3R2-S2, 22.3R3-S1 Juniper Networks Junos OS versions prior to 22.4R2-S1, 22.4R3 Juniper Networks Junos OS Evolved versions prior to 20.4R3-S8-EVO Juniper Networks Junos OS Evolved versions 21.1R1-EVO and later Juniper Networks Junos OS Evolved versions prior to 21.2R3-S6-EVO Juniper Networks Junos OS Evolved versions prior to 21.3R3-S5-EVO Juniper Networks Junos OS Evolved versions prior to 21.4R3-S5-EVO Juniper Networks Junos OS Evolved versions prior to 22.1R3-S4-EVO Juniper Networks Junos OS Evolved versions prior to 22.2R3-S2-EVO Juniper Networks Junos OS Evolved versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO Juniper Networks Junos OS Evolved versions prior to 22.4R2-S1-EVO, 22.4R3-EVO

Description The issue is related to an improper handling of exceptional conditions in AS PATH processing of Juniper Networks Junos OS and Junos OS Evolved. This allows an attacker to send a BGP update message with an AS PATH containing a large number of 4-byte ASes, leading to a Denial of Service (DoS). The issue occurs when the router has Non-Stop Routing (NSR) enabled, has a non-4-byte-AS capable BGP neighbor, receives a BGP update message with a prefix that includes a long AS PATH containing a large number of 4-byte ASes, and has to advertise the prefix towards the non-4-byte-AS capable BGP neighbor.

Recommendations For Juniper Networks Junos OS versions prior to 20.4R3-S8, update to version 20.4R3-S8 or later. For Juniper Networks Junos OS versions 21.1R1 and later, update to version 21.2R3-S6 or later. For Juniper Networks Junos OS versions prior to 21.2R3-S6, update to version 21.2R3-S6 or later. For Juniper Networks Junos OS versions prior to 21.3R3-S5, update to version 21.3R3-S5 or later. For Juniper Networks Junos OS versions prior to 21.4R3-S5, update to version 21.4R3-S5 or later. For Juniper Networks Junos OS versions prior to 22.1R3-S4, update to version 22.1R3-S4 or later. For Juniper Networks Junos OS versions prior to 22.2R3-S2, update to version 22.2R3-S2 or later. For Juniper Networks Junos OS versions prior to 22.3R2-S2, 22.3R3-S1, update to version 22.3R2-S2 or later. For Juniper Networks Junos OS versions prior to 22.4R2-S1, 22.4R3, update to version 22.4R2-S1 or later. For Juniper Networks Junos OS Evolved versions prior to 20.4R3-S8-EVO, update to version 20.4R3-S8-EVO or later. For Juniper Networks Junos OS Evolved versions 21.1R1-EVO and later, update to version 21.2R3-S6-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 21.2R3-S6-EVO, update to version 21.2R3-S6-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 21.3R3-S5-EVO, update to version 21.3R3-S5-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 21.4R3-S5-EVO, update to version 21.4R3-S5-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 22.1R3-S4-EVO, update to version 22.1R3-S4-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 22.2R3-S2-EVO, update to version 22.2R3-S2-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO, update to version 22.3R2-S2-EVO or later. For Juniper Networks Junos OS Evolved versions prior to 22.4R2-S1-EVO, 22.4R3-EVO, update to version 22.4R2-S1-EVO or later.