CVE-2020-1650 in Junos MX
Summary
by MITRE
On Juniper Networks Junos MX Series with service card configured, receipt of a stream of specific packets may crash the MS-PIC component on MS-MIC or MS-MPC. By continuously sending these specific packets, an attacker can repeatedly bring down MS-PIC on MS-MIC/MS-MPC causing a prolonged Denial of Service. This issue affects MX Series devices using MS-PIC, MS-MIC or MS-MPC service cards with any service configured. This issue affects Juniper Networks Junos OS on MX Series: 17.2R2-S7; 17.3R3-S4, 17.3R3-S5; 17.4R2-S4 and the subsequent SRs (17.4R2-S5, 17.4R2-S6, etc.); 17.4R3; 18.1R3-S3, 18.1R3-S4, 18.1R3-S5, 18.1R3-S6, 18.1R3-S7, 18.1R3-S8; 18.2R3, 18.2R3-S1, 18.2R3-S2; 18.3R2 and the SRs based on 18.3R2; 18.4R2 and the SRs based on 18.4R2; 19.1R1 and the SRs based on 19.1R1; 19.2R1 and the SRs based on 19.2R1; 19.3R1 and the SRs based on 19.3R1.
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Analysis
by VulDB Data Team • 11/04/2020
The vulnerability described in CVE-2020-1650 represents a critical denial of service flaw affecting Juniper Networks MX Series routers equipped with MS-PIC service cards. This issue specifically targets the MS-MIC and MS-MPC components within these devices, creating a persistent threat that can be exploited through carefully crafted packet streams to repeatedly crash the affected hardware modules. The vulnerability demonstrates a fundamental weakness in the packet processing mechanisms of these network devices, where legitimate network traffic can be leveraged to create a sustained disruption of service.
The technical flaw manifests when specific sequences of packets are received by the MS-PIC component, causing it to crash and subsequently requiring manual intervention or reboot to restore normal operation. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions that can lead to system instability and denial of service. The attack vector is particularly concerning because it requires only the transmission of specific packet streams rather than complex exploitation techniques, making it accessible to attackers with minimal technical expertise. The vulnerability affects multiple software releases across different Junos OS versions, indicating a persistent flaw that was not adequately addressed in the affected codebase.
The operational impact of this vulnerability extends beyond simple service disruption, as the repeated crashing of MS-PIC components can lead to extended periods of network unavailability that may affect critical infrastructure operations. Network administrators face the challenge of maintaining service availability while dealing with the potential for repeated attacks, especially in environments where these devices serve as core network components. The affected hardware configurations include various service cards that are essential for providing network services, making the impact particularly severe for organizations relying on these platforms. This vulnerability directly relates to ATT&CK technique T1499.004, which covers network denial of service attacks targeting network infrastructure components.
The remediation approach for CVE-2020-1650 requires organizations to implement immediate software updates from Juniper Networks to address the underlying code flaws that cause the MS-PIC component to crash. Network security teams should also consider implementing packet filtering rules to identify and block the specific packet patterns that trigger the vulnerability, though this approach may not be foolproof given the nature of the attack vectors. Additionally, organizations should establish monitoring procedures to detect unusual patterns of MS-PIC crashes or restarts that could indicate attempted exploitation. The vulnerability underscores the importance of maintaining current security patches and implementing robust network segmentation strategies to limit the impact of such attacks on critical network infrastructure.