// For flags

CVE-2025-21591

Junos OS: An unauthenticated adjacent attacker sending a malformed DHCP packet causes jdhcpd to crash

Severity Score

7.1
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS, when DHCP snooping is enabled, allows an unauthenticated, adjacent, attacker to send a DHCP packet with a malformed DHCP option to cause jdhcp to crash creating a Denial of Service (DoS) condition. Continuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition. This issue affects Junos OS: * from 23.1 before 23.2R2-S3, * from 23.4 before 23.4R2-S3, * from 24.2 before 24.2R2. This issue isn't applicable to any versions of Junos OS before 23.1R1. This issue doesn't affect vSRX Series which doesn't support DHCP Snooping. This issue doesn't affect Junos OS Evolved. There are no indicators of compromise for this issue.

*Credits: N/A
CVSS Scores
Attack Vector
Adjacent
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
None
None
Integrity
None
None
Availability
High
Low
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Adjacent
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-12-26 CVE Reserved
  • 2025-04-09 CVE Published
  • 2025-04-28 CVE Updated
  • 2025-05-11 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-805: Buffer Access with Incorrect Length Value
CAPEC
References (1)
URL Tag Source
URL Date SRC
URL Date SRC
URL Date SRC
https://supportportal.juniper.net/JSA96448 2025-04-28
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Juniper Networks
Search vendor "Juniper Networks"
 Junos OS
Search vendor "Juniper Networks" for product "Junos OS"
 >= 23.1 < 23.2R2-S3
Search vendor "Juniper Networks" for product "Junos OS" and version " >= 23.1 < 23.2R2-S3"
en
Affected
Juniper Networks
Search vendor "Juniper Networks"
 Junos OS
Search vendor "Juniper Networks" for product "Junos OS"
 >= 23.4 < 23.4R2-S3
Search vendor "Juniper Networks" for product "Junos OS" and version " >= 23.4 < 23.4R2-S3"
en
Affected
Juniper Networks
Search vendor "Juniper Networks"
 Junos OS
Search vendor "Juniper Networks" for product "Junos OS"
 >= 24.2 < 24.2R2
Search vendor "Juniper Networks" for product "Junos OS" and version " >= 24.2 < 24.2R2"
en
Affected