Junos OS: EX4300: PFE Denial of Service (DoS) upon receipt of a flood of specific ARP traffic

published 2022-04-14 4 y ago modified 2026-06-17 4 mo ago also EUVD-2022-27338

cvss: 6.5; 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

A Denial of Service (DoS) vulnerability in the processing of a flood of specific ARP traffic in Juniper Networks Junos OS on the EX4300 switch, sent from the local broadcast domain, may allow an unauthenticated network-adjacent attacker to trigger a PFEMAN watchdog timeout, causing the Packet Forwarding Engine (PFE) to crash and restart. After the restart, transit traffic will be temporarily interrupted until the PFE is reprogrammed. In a virtual chassis (VC), the impacted Flexible PIC Concentrator (FPC) may split from the VC temporarily, and join back into the VC once the PFE restarts. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS on the EX4300: All versions prior to 15.1R7-S12; 18.4 versions prior to 18.4R2-S10, 18.4R3-S11; 19.1 versions prior to 19.1R3-S8; 19.2 versions prior to 19.2R1-S9, 19.2R3-S4; 19.3 versions prior to 19.3R3-S5; 19.4 versions prior to 19.4R2-S6, 19.4R3-S7; 20.1 versions prior to 20.1R3-S3; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3-S1; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R2-S1, 21.2R3; 21.3 versions prior to 21.3R1-S2, 21.3R2.

Patch / fix

fixed in 1

Juniper Networks Junos OS 15.1R7-S12, 18.4R2-S10, 18.4R3-S11, 19.1R3-S8, 19.2R1-S9, 19.2R3-S4, 19.3R3-S5, 19.4R2-S6, 19.4R3-S7, 20.1R3-S3, 20.2R3-S3, 20.3R3-S2, 20.4R3-S1, 21.1R3, 21.2R2-S1, 21.2R3, 21.3R1-S2, 21.3R2

Exploit prediction

0.37% 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	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
NVD	2.0	6.1	AV:A/AC:L/Au:N/C:N/I:N/A:C

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-410 Insufficient Resource Pool
CWE-400 Uncontrolled Resource Consumption

References

kb.juniper.net /JSA69502
vendor-advisory

Sources

CVE List CVE-2022-22191
NVD CVE-2022-22191

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.

Summary