CVE-2021-0267 Junos OS: Receipt of a crafted DHCP packet will cause the jdhcpd DHCP service to core.

High 7.4 Published 22 Apr 2021 Updated 17 Sep 2024

An attacker can cause a sustained Denial of Service by sending crafted DHCP packets to the jdhcpd service in Junos OS.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-0267?

CVE-2021-0267 is a high-severity denial of service vulnerability in Juniper Junos, published on 22 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

Weakness: CWE-20

Which versions are affected by CVE-2021-0267?

It affects 1 product.

Products include Juniper Junos.

How do I fix CVE-2021-0267?

No fix has been published for CVE-2021-0267 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-0267 being exploited?

There is no known exploitation of CVE-2021-0267 in the wild and no public exploit code.

All Juniper Junos vulnerabilities

Sources

Also known as GHSA-m6p4-4cgp-9hfh.