An Improper Input Validation vulnerability in the Juniper DHCP Daemon (jdhcpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause the jdhcpd process to crash resulting in a Denial of Service (DoS).

When a specifically malformed DHCP packet is received from a DHCP client, the jdhcpd process crashes, impacting network traffic. The DHCP process will restart automatically to recover the service.

This issue will occur when dhcp-security is enabled. 

This issue affects Junos OS: 

• All versions before 21.2R3-S9, 
• from 21.4 before 21.4R3-S10, 
• from 22.2 before 22.2R3-S6, 
• from 22.4 before 22.4R3-S6, 
• from 23.2 before 23.2R2-S3, 
• from 23.4 before 23.4R2-S4, 
• from 24.2 before 24.2R2; 

Junos OS Evolved: 

• from 22.4 before 22.4R3-S6-EVO, 
• from 23.2 before 23.2R2-S3-EVO, 
• from 23.4 before 23.4R2-S4-EVO, 
• from 24.2 before 24.2R2-EVO.

The following software releases have been updated to resolve this specific issue:

Junos OS Evolved: 22.4R3-S6-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.

Junos: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases.

This issue is being tracked as 1842682 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

There are no known workarounds for this issue.

2025-04-09: Initial Publication
2025-04-15: Corrected Severity Level to align with CVSS v3.1 severity rating

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team