CVE-2021-0267

HIGH

Juniper Junos OS 19.4-20.3 - Denial of Service via Crafted DHCP Packet in JDHCPD DHCP Relay Agent

Title source: llm
STIX 2.1

Description

An Improper Input Validation vulnerability in the active-lease query portion in JDHCPD's DHCP Relay Agent of Juniper Networks Junos OS allows an attacker to cause a Denial of Service (DoS) by sending a crafted DHCP packet to the device thereby crashing the jdhcpd DHCP service. This is typically configured for Broadband Subscriber Sessions. Continued receipt and processing of this crafted packet will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS: 19.4 versions prior to 19.4R3-S1; 20.1 versions prior to 20.1R2-S1, 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R2. This issue does not affect Junos OS Evolved.

Scores

CVSS v3 7.4
EPSS 0.0007
EPSS Percentile 21.2%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Details

CWE
CWE-20
Status published
Products (4)
juniper/junos 19.4 r1 (7 CPE variants)
juniper/junos 20.1 r1 (6 CPE variants)
juniper/junos 20.2 r1 (8 CPE variants)
juniper/junos 20.3 r1 (2 CPE variants)
Published Apr 22, 2021
Tracked Since Feb 18, 2026