CVE-2025-52960 in Junos OS
Summary
by MITRE • 10/09/2025
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.
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Analysis
by VulDB Data Team • 12/01/2025
The vulnerability described in CVE-2025-52960 represents a critical buffer management flaw within the Session Initialization Protocol Application Layer Gateway of Juniper Networks Junos OS operating on MX and SRX series devices. This issue manifests as a buffer copy without proper size validation of input data, creating an exploitable condition that can be leveraged by unauthenticated attackers to induce denial of service scenarios. The flaw specifically impacts the flowd and mspmand processes which are responsible for session management and flow monitoring within the network infrastructure.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the SIP ALG component where incoming packets are processed without proper bounds checking. When these specific SIP packets are received under conditions of high memory utilization, the system's memory management structures become compromised leading to process crashes. This behavior aligns with CWE-121, which describes buffer overflow conditions resulting from insufficient input validation, and specifically manifests as a CWE-787, representing out-of-bounds write conditions that can occur when buffer boundaries are not properly enforced. The vulnerability is particularly concerning because it operates at the network layer where attackers can craft malicious SIP packets to trigger the memory corruption without requiring authentication credentials.
From an operational perspective, this vulnerability presents a significant risk to network availability and service stability. While the system demonstrates automatic recovery mechanisms, the disruption periods can severely impact network operations and may require manual intervention to restore full functionality. The sustained denial of service condition becomes particularly problematic when attackers can maintain continuous packet flooding while the system remains in high utilization states. This behavior maps to ATT&CK technique T1499.004, which describes network denial of service attacks, and represents a classic example of how memory corruption vulnerabilities can be exploited to create persistent service interruptions. The timing and conditions required for exploitation make this a particularly insidious threat as attackers do not need to control memory utilization directly, but can instead rely on the natural network traffic patterns to trigger the vulnerability.
The affected product lines include multiple versions of Junos OS across both MX and SRX series platforms, spanning from older releases through specific patch levels. Organizations running versions prior to 22.4R3-S7, or within the specified version ranges from 23.2 before 23.2R2, 23.4 before 23.4R2-S5, and 24.2 before 24.2R2, remain at risk. Mitigation strategies should focus on immediate patch deployment to the recommended versions, network segmentation to limit exposure, and implementation of traffic filtering rules to block suspicious SIP packets. Additionally, monitoring systems should be enhanced to detect unusual memory utilization patterns and process crash events that may indicate exploitation attempts. The vulnerability underscores the importance of robust input validation in network infrastructure software and highlights the critical need for continuous security assessments of core network services.