CVE-2025-21591: A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS, when DHCP snooping is enabled, allows an…

PriorityP339high7.4CVSS 3.1

AVAACLPRNUINSCCNINAH

EPSS

0.32%

24.5th percentile

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.

Affected

9 ranges

Vendor	Product	Version range	Fixed in
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos_os	—	—
juniper	srx_series	—	—
juniper_networks	junos_os	>= 23.1 < 23.2R2-S3	23.2R2-S3
juniper_networks	junos_os	>= 23.4 < 23.4R2-S3	23.4R2-S3
juniper_networks	junos_os	>= 24.2 < 24.2R2	24.2R2

CVSS provenance

nvdv3.17.4HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

nvdv4.07.1HIGHCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:C/RE:M/U:Green

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