CVE-2025-52985: Junos OS Evolved: When a control-plane firewall filter refers to a prefix-list with more than 10 entries it's not matching

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-11 · updated 2026-06-17
Weakness: CWE-480

Description

A Use of Incorrect Operator vulnerability in the Routing Engine firewall of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to bypass security restrictions. When a firewall filter which is applied to the lo0 or re:mgmt interface references a prefix list with 'from prefix-list', and that prefix list contains more than 10 entries, the prefix list doesn't match and packets destined to or from the local device are not filtered. This issue affects firewall filters applied to the re:mgmt interfaces as input and output, but only affects firewall filters applied to the lo0 interface as output. This issue is applicable to IPv4 and IPv6 as a prefix list can contain IPv4 and IPv6 prefixes. This issue affects Junos OS Evolved: * 23.2R2-S3-EVO versions before 23.2R2-S4-EVO, * 23.4R2-S3-EVO versions before 23.4R2-S5-EVO, * 24.2R2-EVO versions before 24.2R2-S1-EVO, * 24.4-EVO versions before 24.4R1-S3-EVO, 24.4R2-EVO. This issue doesn't affect Junos OS Evolved versions before 23.2R1-EVO.

Affected products

Juniper Networks Junos OS Evolved: 23.2-r2-s3, 23.4-r2-s3, 23.4-r2-s4, 24.2-r2, 24.4, 24.4-r1 (+2)

References

https://supportportal.juniper.net/JSA100091

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