Juniper Junos OS up to 21.2R3-S8/22.2R3-S5/22.4R3-S5 on MX SIP ALG denial of service

Summaryinfo

A vulnerability classified as critical has been found in Juniper Junos OS up to 21.2R3-S8/22.2R3-S5/22.4R3-S5 on MX. The impacted element is an unknown function of the component SIP ALG. This manipulation causes denial of service. This vulnerability only affects products that are no longer supported by the maintainer. This vulnerability is tracked as CVE-2025-52982. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Juniper Junos OS up to 21.2R3-S8/22.2R3-S5/22.4R3-S5 on MX and classified as critical. Affected by this vulnerability is some unknown processing of the component SIP ALG. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

An Improper Resource Shutdown or Release vulnerability in the SIP ALG of Juniper Networks Junos OS on MX Series with MS-MPC allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an MX Series device with an MS-MPC is configured with two or more service sets which are both processing SIP calls, a specific sequence of call events will lead to a crash and restart of the MS-MPC. This issue affects Junos OS: * all versions before 21.2R3-S9, * 21.4 versions from 21.4R1, * 22.2 versions before 22.2R3-S6, * 22.4 versions before 22.4R3-S6. As the MS-MPC is EoL after Junos OS 22.4, later versions are not affected. This issue does not affect MX-SPC3 or SRX Series devices.

It is possible to read the advisory at supportportal.juniper.net. This vulnerability is known as CVE-2025-52982 since 06/23/2025. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 21.2R3-S9, 21.4*, 22.2R3-S6 or 22.4R3-S6 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1519). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Juniper MX Series
• Juniper JUNOS
• Juniper SRX Series
• Juniper Security Director
• Juniper Junos Space

Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos OS

Version

• 21.2R3-S8
• 22.2R3-S5
• 22.4R3-S5

License

• commercial

Support

• end of life

Website

• Vendor: https://www.juniper.net/

CPE 2.3info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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