Junos OS: SRX Series: Transmission of specific control traffic sent out of a DS-Lite tunnel results in flowd crash

published 2025-04-09 19 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-10520

cvss: 7.5; 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 37%
public exploits: 0; none known

A NULL Pointer Dereference vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an attacker causing specific, valid control traffic to be sent out of a Dual-Stack (DS) Lite tunnel to crash the flowd process, resulting in a Denial of Service (DoS). Continuous triggering of specific control traffic will create a sustained Denial of Service (DoS) condition.

On all SRX platforms, when specific, valid control traffic needs to be sent out of a DS-Lite tunnel, a segmentation fault occurs within the flowd process, resulting in a network outage until the flowd process restarts.

This issue affects Junos OS on SRX Series: * All versions before 21.2R3-S9, * from 21.4 before 21.4R3-S9, * from 22.2 before 22.2R3-S5, * from 22.4 before 22.4R3-S6, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2.

Patch / fix

fixed in 1

Juniper Networks Junos OS 21.2R3-S9, 21.4R3-S9, 22.2R3-S5, 22.4R3-S6, 23.2R2-S3, 23.4R2

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 19 mo ago (2025-04-09)

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% 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
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A/V:C/RE:M/U:Green
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:C/RE:M/U:Green

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-476 NULL Pointer Dereference

References

supportportal.juniper.net /JSA96455
vendor-advisory

Sources

CVE List CVE-2025-30645
NVD CVE-2025-30645

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