CVE-2024-30390: Junos OS Evolved: Connection limits is not being enforced while the resp. rate limit is being enforced

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-12 · updated 2026-06-17
Weakness: CWE-307

Description

An Improper Restriction of Excessive Authentication Attempts vulnerability in Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a limited Denial of Service (DoS) to the management plane. When an incoming connection was blocked because it exceeded the connections-per-second rate-limit, the system doesn't consider existing connections anymore for subsequent connection attempts so that the connection limit can be exceeded. This issue affects Junos OS Evolved: * All versions before 21.4R3-S4-EVO, * 22.1-EVO versions before 22.1R3-S3-EVO, * 22.2-EVO versions before 22.2R3-S2-EVO, * 22.3-EVO versions before 22.3R2-S1-EVO, 22.3R3-EVO.

Affected products

Juniper Networks Junos OS Evolved: before 21.4; 21.4, 21.4-r1, 21.4-r1-s1, 21.4-r1-s2, 21.4-r2, 21.4-r2-s1 (+28) — fixed in 21.4

How to fix

Upgrade to a fixed version: Juniper Networks Junos OS Evolved 21.4. Check the vendor advisory for mitigations.

References

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