CVE-2021-31384: Juniper Junos

Critical severity, CVSS 10.0. EPSS: 1.2% chance of exploitation in the next 30 days.

Due to a Missing Authorization weakness and Insufficient Granularity of Access Control in a specific device configuration, a vulnerability exists in Juniper Networks Junos OS on SRX Series whereby an attacker who attempts to access J-Web administrative interfaces can successfully do so from any device interface regardless of the web-management configuration and filter rules which may otherwise protect access to J-Web. This issue affects: Juniper Networks Junos OS SRX Series 20.4 version 20.4R1 and later versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2. This issue does not affect Juniper Networks Junos OS versions prior to 20.4R1.

Affected products

• Juniper Junos: version 20.4 only; version 21.1 only

Published 2021-10-19. Last modified 2026-06-17.