CVE-2025-21595

Junos OS and Junos OS Evolved: In an EVPN-VXLAN scenario specific ARP or NDP packets cause FPC to crash

MEDIUM

6.5

CVSS Score

Published: April 9, 2025 at 07:50 PM UTC

Updated: June 17, 2026 at 08:43 AM UTC

3 products affected across 2 vendorsJunosJunos OS EvolvedJunos OS Evolved

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.3%

SSVC

No known exploit

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS). On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart. This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command. user@host> show chassis fpc Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer 0 Online 45 3 0 2 2 2 32768 19 0 <<<<<<< Heap increase in all fPCs This issue affects Junos OS: * All versions before 21.2R3-S7, * 21.4 versions before 21.4R3-S4, * 22.2 versions before 22.2R3-S1, * 22.3 versions before 22.3R3-S1, * 22.4 versions before 22.4R2-S2, 22.4R3. and Junos OS Evolved: * All versions before 21.2R3-S7-EVO, * 21.4-EVO versions before 21.4R3-S4-EVO, * 22.2-EVO versions before 22.2R3-S1-EVO, * 22.3-EVO versions before 22.3R3-S1-EVO, * 22.4-EVO versions before 22.4R3-EVO.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

v < 21.2v < 21.2R3-S721.4 ≤ v < 21.4R3-S422.2 ≤ v < 22.2R3-S122.3 ≤ v < 22.3R3-S122.4 ≤ v < 22.4R2-S2, 22.4R321.2 21.2 r1 21.2 r1-s1 21.2 r1-s2 21.2 r2 21.2 r2-s1 21.2 r2-s2 21.2 r3 21.2 r3-s1 21.2 r3-s2 21.2 r3-s3 21.2 r3-s4 21.2 r3-s5 21.2 r3-s6 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 21.4 r3-s4 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.2 r2 22.2 r2-s1 22.2 r2-s2 22.2 r3 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.3 r2-s1 22.3 r2-s2 22.3 r3 22.4 22.4 r1 22.4 r1-s1 22.4 r1-s2 22.4 r2 22.4 r2-s1 22.4 r3

Affected range stops below 21.2R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R2-S2, 22.4R3, so it looks safe — our inference, not a vendor statement

Junos OS Evolved · Juniper Networks

60%

v < 21.2R3-S7-EVO21.4-EVO ≤ v < 21.4R3-S4-EVO22.2-EVO ≤ v < 22.2R3-S1-EVO22.3-EVO ≤ v < 22.3R3-S1-EVO22.4-EVO ≤ v < 22.4R3-EVO21.4-EVO 22.2-EVO 22.3-EVO 22.4-EVO

Affected range stops below 21.2R3-S7-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S4-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S1-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3-S1-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R3-EVO, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://supportportal.juniper.net/JSA96450

References (1)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA96450

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMjuniper

Attack Vector: ADJACENT_NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusANALYZED

CWE

CWE-401

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