Junos OS (SRX firewalls)
CVE-2025-30644: EX2300, EX3400, EX4000 Series, QFX5k Series: Receipt of a specific DHCP packet causes FPC crash when DHCP Option 82 is enabled
A Heap-based Buffer Overflow vulnerability in the flexible PIC concentrator (FPC) of Juniper Networks Junos OS on EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, and QFX5k Series allows an attacker to send a specific DHCP packet to the device, leading to an FPC crash and restart, resulting in a 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 (EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, QFX5k Series) 0 | 21.4R3-S9 or later |
| Junos OS (EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, QFX5k Series) 22.2 | 22.2R3-S5 or later |
| Junos OS (EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, QFX5k Series) 22.4 | 22.4R3-S5 or later |
| Junos OS (EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, QFX5k Series) 23.2 | 23.2R2-S3 or later |
| Junos OS (EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, QFX5k Series) 23.4 | 23.4R2-S3 or later |
| Junos OS (EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, QFX5k Series) 24.2 | 24.2R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A Heap-based Buffer Overflow vulnerability in the flexible PIC concentrator (FPC) of Juniper Networks Junos OS on EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, and QFX5k Series allows an attacker to send a specific DHCP packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
Under a rare timing scenario outside the attacker's control, memory corruption may be observed when DHCP Option 82 is enabled, leading to an FPC crash and affecting packet forwarding. Due to the nature of the heap-based overflow, exploitation of this vulnerability could also lead to remote code execution within the FPC, resulting in complete control of the vulnerable component. This issue affects Junos OS on EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, and QFX5k Series:
- All versions before 21.4R3-S9,
- from 22.2 before 22.2R3-S5,
- from 22.4 before 22.4R3-S5,
- from 23.2 before 23.2R2-S3,
- from 23.4 before 23.4R2-S3,
- from 24.2 before 24.2R2.
Am I affected?
This issue only occurs when DHCP forwarding-options Option 82 is enabled, as shown below:
[vlans <name> forwarding-options dhcp-security option-82]
Workarounds
Disable dhcp-option82 if it is not required.
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.