CVE-2021-0235 Missing authorization in Junos OS
Tenant administrators can bypass isolation to intercept or modify traffic from other tenants due to incorrect permission schemes.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-0235?
CVE-2021-0235 is a high-severity missing authorization 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
On SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3, vSRX Series devices using tenant services on Juniper Networks Junos OS, due to incorrect permission scheme assigned to tenant system administrators, a tenant system administrator may inadvertently send their network traffic to one or more tenants while concurrently modifying the overall device system traffic management, affecting all tenants and the service provider. Further, a tenant may inadvertently receive traffic from another tenant. This issue affects: Juniper Networks Junos OS 18.3 version 18.3R1 and later versions on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.4 version 18.4R1 and later versions on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.1 versions 19.1R1 and later versions on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.3 versions prior to 19.3R3-S2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.4 versions prior to 19.4R2-S4, 19.4R3-S2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 20.1 versions prior to 20.1R2, 20.1R3 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3 vSRX Series; 20.2 versions prior to 20.2R2-S1, 20.2R3 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3 vSRX Series; 20.3 versions prior to 20.3R1-S2, 20.3R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3 vSRX Series; 20.4 versions prior to 20.4R1, 20.4R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3 vSRX Series. This issue does not affect Juniper Networks Junos OS versions prior to 18.3R1.
Weakness: CWE-276
Which versions are affected by CVE-2021-0235?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2021-0235?
No fix has been published for CVE-2021-0235 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-0235 being exploited?
There is no known exploitation of CVE-2021-0235 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-3w49-97mp-g27g.