CVE-2024-39533: Junos OS: QFX5000 Series and EX4600 Series: Output firewall filter is not applied if certain match criteria are used

Severity: medium (CVSS 5.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-11 · updated 2026-06-17
Weakness: CWE-447

Description

An Unimplemented or Unsupported Feature in the UI vulnerability in Juniper Networks Junos OS on QFX5000 Series and EX4600 Series allows an unauthenticated, network-based attacker to cause a minor integrity impact to downstream networks.If one or more of the following match conditions ip-source-address ip-destination-address arp-type which are not supported for this type of filter, are used in an ethernet switching filter, and then this filter is applied as an output filter, the configuration can be committed but the filter will not be in effect. This issue affects Junos OS on QFX5000 Series and EX4600 Series: * All version before 21.2R3-S7, * 21.4 versions before 21.4R3-S6, * 22.1 versions before 22.1R3-S5, * 22.2 versions before 22.2R3-S3, * 22.3 versions before 22.3R3-S2, * 22.4 versions before 22.4R3, * 23.2 versions before 23.2R2. Please note that the implemented fix ensures these unsupported match conditions cannot be committed anymore.

Affected products

Juniper Junos OS: before 21.2; 21.2, 21.2-r1, 21.2-r1-s1, 21.2-r1-s2, 21.2-r2, 21.2-r2-s1 (+63) — fixed in 21.2

How to fix

Upgrade to a fixed version: Juniper Junos OS 21.2. Check the vendor advisory for mitigations.

References

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