CVE-2025-21591 - CVE House
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Status published High CVE-2025-21591

Junos OS: An unauthenticated adjacent attacker sending a malformed DHCP packet causes jdhcpd to crash

Vulnerability 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 23.1 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Juniper Networks

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Affected Software

Junos OS
Vulnerable Versions:
23.1, 23.4, 24.2, 0

Timeline

Official Publish: April 9th, 2025
Last Modified: April 28th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Weaknesses (CWE)

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.