vulnerability
Juniper Junos OS: 2021-04 Security Bulletin: Junos OS: Receipt of a crafted DHCP packet will cause the jdhcpd DHCP service to core. (JSA11158) (CVE-2021-0267)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 3 | (AV:A/AC:L/Au:N/C:N/I:N/A:P) | Apr 22, 2021 | Apr 27, 2021 | Mar 27, 2026 |
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.
Solution
2026 Global Threat Landscape Report
The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.