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Fencer Vulns
high 7.5

CVE-2023-44191 json

Junos OS: QFX5000 Series and EX4000 Series: Denial of Service (DoS) on a large scale VLAN due to PFE hogging

published 2023-10-12 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-48550

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

An Allocation of Resources Without Limits or Throttling vulnerability in Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS).

On all Junos OS QFX5000 Series and EX4000 Series platforms, when a high number of VLANs are configured, a specific DHCP packet will cause PFE hogging which will lead to dropping of socket connections.

This issue affects:

Juniper Networks Junos OS on QFX5000 Series and EX4000 Series

* 21.1 versions prior to 21.1R3-S5; * 21.2 versions prior to 21.2R3-S5; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2.

This issue does not affect Juniper Networks Junos OS versions prior to 21.1R1

Patch / fix

  • Juniper Networks Junos OS 21.1R3-S5, 21.2R3-S5, 21.3R3-S5, 21.4R3-S4, 22.1R3-S3, 22.2R3-S1, 22.3R2-S2, 22.3R3, 22.4R2
  • juniper_networks junos_os 21.1r1, 21.1r3-s5, 21.2r3-s5, 21.3r3-s5, 21.4r3-s4, 22.2r3-s1, 22.3r2-s2, 22.4r2, ss.1r3-s3

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.62% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Juniper Networks Junos OS
  • juniper_networks junos_os

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

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.