CVE-2024-30405: SRX 5000 Series with SPC2: Processing of specific crafted packets when ALG is enabled causes a transit traffic Denial of Service

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 with SPC2) 0	21.2R3-S7 or later
Junos OS (SRX 5000 Series with SPC2) 21.4	21.4R3-S6 or later
Junos OS (SRX 5000 Series with SPC2) 22.1	22.1R3-S5 or later
Junos OS (SRX 5000 Series with SPC2) 22.2	22.2R3-S3 or later
Junos OS (SRX 5000 Series with SPC2) 22.3	22.3R3-S2 or later
Junos OS (SRX 5000 Series with SPC2) 22.4	22.4R3 or later
Junos OS (SRX 5000 Series with SPC2) 23.2	23.2R2 or later

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

What it is

An Incorrect Calculation of Buffer Size vulnerability in Juniper Networks Junos OS SRX 5000 Series devices using SPC2 line cards while ALGs are enabled allows an attacker sending specific crafted packets to cause a transit traffic Denial of Service (DoS).

Continued receipt and processing of these specific packets will sustain the Denial of Service condition.

This issue affects: Juniper Networks Junos OS SRX 5000 Series with SPC2 with ALGs enabled. * All versions earlier than 21.2R3-S7; * 21.4 versions earlier than 21.4R3-S6; * 22.1 versions earlier than 22.1R3-S5; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R2.

Am I affected?

The following minimum configuration is required to be exposed to the issue:

[security alg]

Workarounds

There are no known workarounds for this issue other than reducing risk by disabling as many ALGs as possible until the device can be upgraded.

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.