CVE-2024-21594: SRX 5000 Series: Repeated execution of a specific CLI command causes a flowd crash

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 (SRX 5000 Series) 0	20.4R3-S6 or later
Junos OS (SRX 5000 Series) 21.1	21.1R3-S5 or later
Junos OS (SRX 5000 Series) 21.2	21.2R3-S4 or later
Junos OS (SRX 5000 Series) 21.3	21.3R3-S3 or later
Junos OS (SRX 5000 Series) 21.4	21.4R3-S3 or later
Junos OS (SRX 5000 Series) 22.1	22.1R3-S1 or later
Junos OS (SRX 5000 Series) 22.2	22.2R3 or later
Junos OS (SRX 5000 Series) 22.3	22.3R2 or later

Always confirm against the vendor advisory, which lists every fixed hotfix.

What it is

A Heap-based Buffer Overflow vulnerability in the Network Services Daemon (NSD) of Juniper Networks Junos OS allows authenticated, low privileged, local attacker to cause a Denial of Service (DoS).

On an SRX 5000 Series device, when executing a specific command repeatedly, memory is corrupted, which leads to a Flow Processing Daemon (flowd) crash.

The NSD process has to be restarted to restore services.

If this issue occurs, it can be checked with the following command:

user@host> request security policies check The following log message can also be observed:

Error: policies are out of sync for PFE node<number>.fpc<number>.pic<number>. This issue affects:

Juniper Networks Junos OS on SRX 5000 Series

All versions earlier than 20.4R3-S6;
21.1 versions earlier than 21.1R3-S5;
21.2 versions earlier than 21.2R3-S4;
21.3 versions earlier than 21.3R3-S3;
21.4 versions earlier than 21.4R3-S3;
22.1 versions earlier than 22.1R3-S1;
22.2 versions earlier than 22.2R3;
22.3 versions earlier than 22.3R2.

Workarounds

There are no known workarounds for this issue.

Exploitation

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.