An integer overflow or wraparound, identified as CWE-190, occurs in the routing protocol daemon of Juniper Networks Junos OS and Junos OS Evolved when processing malformed OSPFv2 packets. The flaw can trigger a denial of service by causing the router to crash or restart, leading to routing disruption. The impact is limited to availability – an attacker can prevent traffic from passing through the affected node, but there is no direct compromise of confidentiality or integrity.

Juniper Networks’ Junos OS and Junos OS Evolved are affected. The issue applies to releases prior to Junos OS 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 25.4R2, 26.2R1-S2, 26.2R2, 26.4R1 and their subsequent releases, and analogous versions for Junos OS Evolved ending with the listed patch releases. Any device running those versions with OSPF enabled is within risk.

The CVSS score is 7.1, indicating moderate to high severity. The EPSS score is 0.00269 (<1%), and the vulnerability is not listed in the CISA KEV catalog, suggesting that widespread exploitation at the current moment is limited. Nevertheless, an unauthenticated adjacent attacker can send crafted OSPF packets on an interface where OSPF is enabled; the integer overflow can cause the device to reboot. The likely attack vector is a neighboring router or device on the same OSPF network sending malicious packets.