CVE-2025-21591 Information

Description

A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS when DHCP snooping is enabled allows an unauthenticated adjacent attacker to send a DHCP packet with a malformed DHCP option to cause jdhcp to crash creating a Denial of Service (DoS) condition.

Continuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition.

This issue affects Junos OS:

from 23.1R1 before 23.2R2-S3
from 23.4 before 23.4R2-S3
from 24.2 before 24.2R2.

This issue isn’t applicable to any versions of Junos OS before 23.1R1.

This issue doesn’t affect vSRX Series which doesn’t support DHCP Snooping.

This issue doesn’t affect Junos OS Evolved.

There are no indicators of compromise for this issue.

CVSS Vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Reference

https://supportportal.juniper.net/JSA96448

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.4