Junos OS: MX Series and SRX Series: The flow processing daemon (flowd) will crash when specific H.323 packets are received

published 2023-01-12 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-26578

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits: 0; none known

An Out-of-Bounds Write vulnerability in the H.323 ALG of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS). On all MX Series and SRX Series platform, when H.323 ALG is enabled and specific H.323 packets are received simultaneously, a flow processing daemon (flowd) crash will occur. Continued receipt of these specific packets will cause a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS on MX Series and SRX Series All versions prior to 19.4R3-S10; 20.2 versions prior to 20.2R3-S6; 20.3 versions prior to 20.3R3-S6; 20.4 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-S3; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R2-S1, 22.1R3; 22.2 versions prior to 22.2R1-S2, 22.2R2.

Patch / fix

fixed in 1

Juniper Networks Junos OS 19.4R3-S10, 20.2R3-S6, 20.3R3-S6, 20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S3, 21.4R3, 22.1R2-S1, 22.1R3, 22.2R1-S2, 22.2R2

CISA SSVC

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

Exploit prediction

0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

kb.juniper.net https://kb.juniper.net/JSA70211 referenced PoC, tagged "exploit" by a source, unverified

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 /JSA70211
exploit, vendor-advisory

Sources

CVE List CVE-2023-22415
NVD CVE-2023-22415

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