Skip to content
Fencer Vulns
medium 5.8

CVE-2024-30389 json

Junos OS: EX4300 Series: Firewall filter not blocking egress traffic

published 2024-04-12 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-28310

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

An Incorrect Behavior Order vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on EX4300 Series allows an unauthenticated, network-based attacker to cause an integrity impact to networks downstream of the vulnerable device.

When an output firewall filter is applied to an interface it doesn't recognize matching packets but permits any traffic. This issue affects Junos OS 21.4 releases from 21.4R1 earlier than 21.4R3-S6. This issue does not affect Junos OS releases earlier than 21.4R1.

Patch / fix

  • Juniper Networks Junos OS 21.4R3-S6
  • juniper junos 21.4r3-s6

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Juniper Networks Junos OS
  • juniper junos

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.