Junos OS: SRX Series: The flow processing daemon (flowd) will crash when Unified Policies are used with IPv6 and certain dynamic applications are rejected by the device

published 2023-01-12 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-26574

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 50%
public exploits: 0; none known

An Out-of-Bounds Write vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS). On SRX Series devices using Unified Policies with IPv6, when a specific IPv6 packet goes through a dynamic-application filter which will generate an ICMP deny message, the flowd core is observed and the PFE is restarted. This issue affects: Juniper Networks Junos OS on SRX Series: 19.2 versions prior to 19.2R3-S6; 19.3 versions prior to 19.3R3-S6; 19.4 versions prior to 19.4R3-S9; 20.2 versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S4; 20.4 versions prior to 20.4R3-S3; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R3; 21.3 versions prior to 21.3R2; 21.4 versions prior to 21.4R2.

Patch / fix

fixed in 1

Juniper Networks Junos OS 19.2R3-S6, 19.3R3-S6, 19.4R3-S9, 20.2R3-S5, 20.3R3-S4, 20.4R3-S3, 21.1R3, 21.2R3, 21.3R2, 21.4R2

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 19 mo ago (2025-04-07)

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% 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

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-787 Out-of-bounds Write

References

kb.juniper.net /JSA70207
vendor-advisory

Sources

CVE List CVE-2023-22411
NVD CVE-2023-22411

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Summary