CVE-2021-31384: Junos OS: SRX Series: Under a specific device configuration an attacker can access the devices J-Web management services from any interface, regardless of security settings protecting the service

Severity: critical (CVSS 10.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-19 · updated 2026-06-17
Weakness: CWE-285

Description

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 OS: 20.4-r1, 20.4-r1-s1, 20.4-r2, 21.1-r1

References

Get alerted when CVE-2021-31384 or the next vulnerability affects your stack