Junos OS: EX2300, EX3400, EX4000 Series, QFX5k Series: Receipt of a specific DHCP packet causes FPC crash when DHCP Option 82 is enabled

Summary

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.

Timeline

1. Apr 9, 2025, 7:52 PM UTCCVE published
2. Apr 10, 2025, 3:55 AM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Feb 26, 2026, 6:28 PM UTCRecord last updated

Affected versions

• Juniper Networks Junos OS

  fixed in 21.4R3-S9; From 22.2 · fixed in 22.2R3-S5; From 22.4 · fixed in 22.4R3-S5; From 23.2 · fixed in 23.2R2-S3; From 23.4 · fixed in 23.4R2-S3; From 24.2 · fixed in 24.2R2

References 1