CVE-2025-21595

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

Severity Score

7.1

*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

MITRE
TN

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.

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.

*Credits: N/A

CVSS Scores

Attack Vector

Adjacent

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

System

Vulnerable | Subsequent

Confidentiality

None

Integrity

None

Availability

High

Low

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Adjacent

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-12-26 CVE Reserved
2025-04-09 CVE Published
2025-04-10 CVE Updated
2025-04-10 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-401: Missing Release of Memory after Effective Lifetime

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://supportportal.juniper.net/JSA96450	2025-04-10

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Juniper Networks Search vendor "Juniper Networks"		Junos OS Search vendor "Juniper Networks" for product "Junos OS"				< 21.2R3-S7 Search vendor "Juniper Networks" for product "Junos OS" and version " < 21.2R3-S7"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Search vendor "Juniper Networks" for product "Junos OS"				>= 21.4 < 21.4R3-S4 Search vendor "Juniper Networks" for product "Junos OS" and version " >= 21.4 < 21.4R3-S4"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Search vendor "Juniper Networks" for product "Junos OS"				>= 22.2 < 22.2R3-S1 Search vendor "Juniper Networks" for product "Junos OS" and version " >= 22.2 < 22.2R3-S1"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Search vendor "Juniper Networks" for product "Junos OS"				>= 22.3 < 22.3R3-S1 Search vendor "Juniper Networks" for product "Junos OS" and version " >= 22.3 < 22.3R3-S1"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Search vendor "Juniper Networks" for product "Junos OS"				>= 22.4 < 22.4R2-S2 Search vendor "Juniper Networks" for product "Junos OS" and version " >= 22.4 < 22.4R2-S2"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Search vendor "Juniper Networks" for product "Junos OS"				>= 22.4 < 22.4R3 Search vendor "Juniper Networks" for product "Junos OS" and version " >= 22.4 < 22.4R3"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Evolved Search vendor "Juniper Networks" for product "Junos OS Evolved"				< 21.2R3-S7-EVO Search vendor "Juniper Networks" for product "Junos OS Evolved" and version " < 21.2R3-S7-EVO"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Evolved Search vendor "Juniper Networks" for product "Junos OS Evolved"				>= 21.4-EVO < 21.4R3-S4-EVO Search vendor "Juniper Networks" for product "Junos OS Evolved" and version " >= 21.4-EVO < 21.4R3-S4-EVO"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Evolved Search vendor "Juniper Networks" for product "Junos OS Evolved"				>= 22.2-EVO < 22.2R3-S1-EVO Search vendor "Juniper Networks" for product "Junos OS Evolved" and version " >= 22.2-EVO < 22.2R3-S1-EVO"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Evolved Search vendor "Juniper Networks" for product "Junos OS Evolved"				>= 22.3-EVO < 22.3R3-S1-EVO Search vendor "Juniper Networks" for product "Junos OS Evolved" and version " >= 22.3-EVO < 22.3R3-S1-EVO"		en		Affected
Juniper Networks Search vendor "Juniper Networks"		Junos OS Evolved Search vendor "Juniper Networks" for product "Junos OS Evolved"				>= 22.4-EVO < 22.4R3-EVO Search vendor "Juniper Networks" for product "Junos OS Evolved" and version " >= 22.4-EVO < 22.4R3-EVO"		en		Affected