Junos OS (SRX firewalls)
CVE-2024-30392: MX Series with SPC3 and MS-MPC/-MIC: When URL filtering is enabled and a specific URL request is received a flowd crash occurs
A Stack-based Buffer Overflow vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (MX Series with SPC3 and MS-MPC) 0 | 21.2R3-S6 or later |
| Junos OS (MX Series with SPC3 and MS-MPC) 21.3 | 21.3R3-S5 or later |
| Junos OS (MX Series with SPC3 and MS-MPC) 21.4 | 21.4R3-S5 or later |
| Junos OS (MX Series with SPC3 and MS-MPC) 22.1 | 22.1R3-S3 or later |
| Junos OS (MX Series with SPC3 and MS-MPC) 22.2 | 22.2R3-S1 or later |
| Junos OS (MX Series with SPC3 and MS-MPC) 22.3 | 22.3R2-S2, 22.3R3 or later |
| Junos OS (MX Series with SPC3 and MS-MPC) 22.4 | 22.4R2-S1, 22.4R3 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A Stack-based Buffer Overflow vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS).
On all Junos OS MX Series platforms with SPC3 and MS-MPC/-MIC, when URL filtering is enabled and a specific URL request is received and processed, flowd will crash and restart. Continuous reception of the specific URL request will lead to a sustained Denial of Service (DoS) condition.
This issue affects: Junos OS:
- all versions before 21.2R3-S6,
- from 21.3 before 21.3R3-S5,
- from 21.4 before 21.4R3-S5,
- from 22.1 before 22.1R3-S3,
- from 22.2 before 22.2R3-S1,
- from 22.3 before 22.3R2-S2, 22.3R3,
- from 22.4 before 22.4R2-S1, 22.4R3.
Am I affected?
For the issue to occur, following two conditions need to be met:
1. Enable URL filtering: [jservices-urlf enable] 2. Configure the following template: [url-filter-template template {client-interfaces [] server-interfaces [] dns-server <IP_address> url-filter-database <db_name>}]
Workarounds
There are no available workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.