2025-10 Security Bulletin: Junos OS: SRX Series and MX Series: Receipt of specific SIP packets in a high utilization situation causes a flowd/mspmand crash (CVE-2025-52960)

Product Affected

This issue affects all versions of Junos OS. Affected platforms: SRX Series, MX Series.

Severity

Medium

Severity Assessment (CVSS) Score

CVSS: v3.1: 5.9 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVSS: v4.0: 8.2 (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M)

Problem

A Buffer Copy without Checking Size of Input vulnerability in the Session Initialization Protocol (SIP) ALG of Juniper Networks Junos OS on MX Series and SRX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS).

When memory utilization is high, and specific SIP packets are received, flowd/mspmand crashes. While the system recovers automatically, the disruption can significantly impact service stability. Continuous receipt of these specific SIP packets, while high utilization is present, will cause a sustained DoS condition. The utilization is outside the attackers control, so they would not be able to deterministically exploit this.

This issue affects Junos OS on SRX Series and MX Series:

All versions before 22.4R3-S7,
from 23.2 before 23.2R2-S4,
from 23.4 before 23.4R2-S5,
from 24.2 before 24.2R2.

To be affected the SIP ALG needs to be enabled, either implicitly / by default or by way of configuration.

Please verify on SRX, and MX with SPC3 with:

user@host> show security alg status | match sip
SIP : Enabled

Please verify on MX whether the following is configured:

[services ... rule <rule-name> (term <term-name> ) from/match application/application-set <name>]

where either

a. name = junos-sip

or an application or application-set refers to SIP:

b. [applications application <name> application-protocol sip]

c. [applications application-set <name> application junos-sip]

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

Solution

The following software releases have been updated to resolve this specific issue: 22.4R3-S7, 23.2R2-S4, 23.4R2-S5, 24.2R2, 24.4R1, and all subsequent releases.

This issue is being tracked as 1819450 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

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 ]

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net], "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History

2025-10-08: Initial Publication