Heap Buffer Overflow in Juniper FPC (Junos OS <21.4R3) - DoS/RCE
CVE-2025-30644 Published on April 9, 2025
Junos OS: 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). 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.
Vulnerability Analysis
Timeline
Initial Publication
Weakness Type
Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Products Associated with CVE-2025-30644
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Affected Versions
Juniper Networks Junos OS:- Before 21.4R3-S9 is affected.
- Version 22.2 and below 22.2R3-S5 is affected.
- Version 22.4 and below 22.4R3-S5 is affected.
- Version 23.2 and below 23.2R2-S3 is affected.
- Version 23.4 and below 23.4R2-S3 is affected.
- Version 24.2 and below 24.2R2 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.