CVE-2025-30656

Junos OS: MX Series, SRX Series: Processing of specific SIP INVITE messages by the SIP ALG will lead to an FPC crash

Description

An Improper Handling of Additional Special Element vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series with MS-MPC, MS-MIC and SPC3, and SRX Series, allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If the SIP ALG processes specifically formatted SIP invites, a memory corruption will occur which will lead to a crash of the FPC processing these packets. Although the system will automatically recover with the restart of the FPC, subsequent SIP invites will cause the crash again and lead to a sustained DoS. This issue affects Junos OS on MX Series and SRX Series:  * all versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S10, * 22.2 versions before 22.2R3-S6, * 22.4 versions before 22.4R3-S5, * 23.2 versions before 23.2R2-S3, * 23.4 versions before 23.4R2-S3, * 24.2 versions before 24.2R1-S2, 24.2R2.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases.

Workaround:

  • There are no known workarounds for this issue. To reduce the risk of exploitation customers not requiring the SIP ALG functionality could explicitly disable it (in case it's by default enabled) by configuring: [ security alg sip disable ]

Category

8.7
CVSS
Severity: High
CVSS 4.0 •
CVSS 3.1 •
EPSS 0.06%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Published at:
Updated at:

References

Link Tags
https://supportportal.juniper.net/JSA96466 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2025-30656?
CVE-2025-30656 has been scored as a high severity vulnerability.
How to fix CVE-2025-30656?
To fix CVE-2025-30656: The following software releases have been updated to resolve this specific issue: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases.
Is CVE-2025-30656 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-30656 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-30656?
CVE-2025-30656 affects Juniper Networks Junos OS.
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