Junos
CVE-2025-30644
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Heap buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.7 (HIGH). Attack characteristics: adjacent network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 0.19%. |
| Exploit ScenarioDerived | Successful exploitation could compromise the high-severity affected system. |
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Alert meAnalysisAIv1 – Mar 28, 2026
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. Rated high severity (CVSS 7.7), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified under CWE-122. 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.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. Affected products include: Juniper Junos. Version information: before 21.4.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:N/R:A/RE:M/U:Green
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
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.
Executive ViewAI
CVE-2025-30644 presents notable security risk, a heap-based buffer overflow vulnerability rated CVSS 7.7. Exploitation could allow attackers to corrupt memory, crash the application, or potentially execute arbitrary code. Organizations should apply vendor updates when available and consider compensating controls in the interim.
Apply vendor patch. If immediate patching is not feasible: (1) Enable ASLR and DEP where available; (2) Implement network segmentation; (3) Monitor for exploitation indicators.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.
Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)CVE.org
named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 does not properly handle DNAME records when parsing fe
named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 allows remote attackers to cause a denial of service (
A security vulnerability in An Improper (CVSS 6.7) that allows a local attacker with high privileges. Risk factors: acti
A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series and SRX Series all
jsdm/ajax/port.php in J-Web in Juniper Junos before 10.4R13, 11.4 before 11.4R7, 12.1 before 12.1R5, 12.2 before 12.2R3,
Juniper Junos 11.4 before R11, 12.1 before R9, 12.1X44 before D30, 12.1X45 before D20, 12.1X46 before D15, 12.1X47 befor
NFX Series devices using Juniper Networks Junos OS are susceptible to a local command execution vulnerability thereby al
NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allow
Insufficient validation of environment variables in the telnet client supplied in Junos OS can lead to stack-based buffe
An Out-of-Bounds Write vulnerability in the H.323 ALG of Juniper Networks Junos OS allows an unauthenticated, network-ba
On QFX10000 Series devices using Juniper Networks Junos OS when configured as transit IP/MPLS penultimate hop popping (P
A Missing Release of Memory after Effective Lifetime vulnerability in the kernel of Juniper Networks Junos OS allows an
GitHub PoC
Exploit-DB