Medium severity · published Apr 9, 2025
CVE-2025-21595
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,…
6.5
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 17% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JO
Junos OS · Juniper
before 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; +34 more · source: NVD
JO
Junos OS Evolved · Juniper
before 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; +34 more · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-21595
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-21595
Vendor Advisory
https://supportportal.juniper.net/JSA96450
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