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Fencer Vulns
medium 6.5

CVE-2023-44203 json

Junos OS: QFX5000 Series, EX2300, EX3400, EX4100, EX4400 and EX4600: Packet flooding will occur when IGMP traffic is sent to an isolated VLAN

published 2023-10-12 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-48562

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

An Improper Check or Handling of Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on QFX5000 Series, EX2300, EX3400, EX4100, EX4400 and EX4600 allows a adjacent attacker to send specific traffic, which leads to packet flooding, resulting in a Denial of Service (DoS).

When a specific IGMP packet is received in an isolated VLAN, it is duplicated to all other ports under the primary VLAN, which causes a flood.

This issue affects QFX5000 series, EX2300, EX3400, EX4100, EX4400 and EX4600 platforms only.

This issue affects Juniper Junos OS on on QFX5000 Series, EX2300, EX3400, EX4100, EX4400 and EX4600:

* All versions prior to 20.4R3-S5; * 21.1 versions prior to 21.1R3-S4; * 21.2 versions prior to 21.2R3-S3; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S2; * 22.1 versions prior to 22.1R3; * 22.2 versions prior to 22.2R3; * 22.3 versions prior to 22.3R2.

Patch / fix

  • Juniper Networks Junos OS 20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S5, 21.4R3-S2, 22.1R3, 22.2R3, 22.3R2

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Juniper Networks Junos OS

Classification

Weakness
  • CWE-703 Improper Check or Handling of Exceptional Conditions

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.