Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2025-21591

Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
09/04/2025
Last modified:
26/01/2026

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.<br /> <br /> Continuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition.<br /> <br /> <br /> This issue affects Junos OS:<br /> <br /> <br /> <br /> * from 23.1 before 23.2R2-S3,<br /> * from 23.4 before 23.4R2-S3,<br /> * from 24.2 before 24.2R2.<br /> <br /> <br /> This issue isn&amp;#39;t applicable to any versions of Junos OS before 23.1R1. <br /> <br /> <br /> <br /> This issue doesn&amp;#39;t affect vSRX Series which doesn&amp;#39;t support DHCP Snooping. <br /> <br /> This issue doesn&amp;#39;t affect Junos OS Evolved.<br /> <br /> There are no indicators of compromise for this issue.

Impact

Vector 4.0
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/V:C/RE:M/U:Green CVSS v4.0 Severity and Metrics:

Base Score: 7.10 HIGH
Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/V:C/RE:M/U:Green

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): None
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): Low
Automatable (AU): Yes
Recovery (R): User
Value Density (V): Concentrated
Vulnerability Response Effort (RE): Moderate
Provider Urgency (U): Green

Base Score 4.0
7.10
Severity 4.0
HIGH
Vector 3.x
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.40 HIGH
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
7.40
Severity 3.x
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:juniper:junos:23.1:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools