Improper Check for Unusual Conditions in Junos OS on MX Series by Juniper Networks
CVE-2025-21594

8.7HIGH

Key Information:

Vendor
Juniper Networks
Status
Junos Os
Vendor
CVE Published:
9 April 2025

Badges

👾 Exploit Exists

Summary

A vulnerability exists in the packet forwarding engine of Junos OS on MX Series that can lead to Denial of Service (DoS) conditions. Specifically, in scenarios involving DS-Lite and NAT, when specially crafted IPv6 traffic is processed with a prefix-length set to 56, affected ports may not be released as expected. This situation can prevent users from establishing new connections, necessitating a manual restart of the affected FPC/PIC for recovery. Notably, this issue impacts multiple versions of Junos OS, with specific versions listed for users to ensure their systems are safeguarded.

Affected Version(s)

Junos OS MX Series 0 < 21.2R3-S8

Junos OS MX Series 21.4 < 21.4R3-S7

Junos OS MX Series 22.1 < 22.1R3-S6

References

https://supportportal.juniper.net/JSA96449
vendor-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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