CVE-2021-0225

Junos OS Evolved: Stateless IP firewall filter does not work as expected

MEDIUM
5.8
CVSS Score
Published: April 22, 2021 at 07:36 PM UTC
Updated: June 17, 2026 at 03:29 AM UTC
2 products affected across 2 vendorsJunos OS EvolvedJunos OS Evolved

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Severity
MEDIUM5.8
Exploit prediction
EPSS 0.7%

Description

An Improper Check for Unusual or Exceptional Conditions in Juniper Networks Junos OS Evolved may cause the stateless firewall filter configuration which uses the action 'policer' in certain combinations with other options to not take effect. An administrator can use the following CLI command to see the failures with filter configuration: user@device> show log kfirewall-agent.log | match ERROR Jul 23 14:16:03 ERROR: filter not supported This issue affects Juniper Networks Junos OS Evolved: Versions 19.1R1-EVO and above prior to 20.3R1-S2-EVO, 20.3R2-EVO. This issue does not affect Juniper Networks Junos OS.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 19.1R1-EVO20.3-EVO ≤ v < 20.3R1-S2-EVO, 20.3R2-EVO19.1R1-EVO20.3-EVO
Affected range stops below 20.3R1-S2-EVO, 20.3R2-EVO, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

x_refsource_MISCVendor Advisory
https://kb.juniper.net/JSA11120

CVSS

5.8MEDIUMjuniper
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-754

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