CVE-2019-0050 in Junos
Summary
by MITRE
Under certain heavy traffic conditions srxpfe process can crash and result in a denial of service condition for the SRX1500 device. Repeated crashes of the srxpfe can result in an extended denial of service condition. The SRX device may fail to forward traffic when this condition occurs. Affected releases are Juniper Networks Junos OS: 15.1X49 versions prior to 15.1X49-D170 on SRX1500; 17.3 versions prior to 17.3R3-S7 on SRX1500; 17.4 versions prior to 17.4R2-S8, 17.4R3 on SRX1500; 18.1 versions prior to 18.1R3-S8 on SRX1500; 18.2 versions prior to 18.2R3 on SRX1500; 18.3 versions prior to 18.3R2 on SRX1500; 18.4 versions prior to 18.4R2 on SRX1500.
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Analysis
by VulDB Data Team • 01/05/2024
The vulnerability identified as CVE-2019-0050 represents a critical denial of service flaw within Juniper Networks SRX1500 series firewalls running specific versions of Junos OS. This issue manifests through the srxpfe process which serves as the packet forwarding engine responsible for traffic processing and forwarding operations. The vulnerability becomes apparent under heavy traffic conditions where the system's processing capacity is exceeded, leading to process crashes that can cascade into extended service interruptions.
The technical root cause of this vulnerability lies in the improper handling of packet processing under high load scenarios within the srxpfe component. When traffic volumes exceed normal operational thresholds, the process fails to properly manage memory allocation and processing queues, resulting in segmentation faults or resource exhaustion that terminates the srxpfe process. This behavior aligns with CWE-129, which addresses improper validation of array indices, and CWE-704, which covers incorrect type conversion or cast operations that can lead to memory corruption. The vulnerability demonstrates characteristics of a resource exhaustion attack pattern where sustained heavy traffic can systematically deplete system resources.
The operational impact of CVE-2019-0050 extends beyond simple service disruption to create significant network reliability issues for organizations relying on SRX1500 devices for security operations. When the srxpfe process crashes repeatedly, the device enters a state where it cannot forward traffic effectively, creating network black holes that can affect business continuity and security posture. The extended denial of service condition occurs because the device fails to automatically recover from these crashes, requiring manual intervention or device reboot to restore normal operations. Network administrators face challenges in maintaining consistent security policies as traffic flows become unpredictable, potentially exposing network segments to unauthorized access during service outages.
The vulnerability affects multiple Junos OS versions across different release branches, specifically targeting SRX1500 hardware platforms with versions 15.1X49 prior to 15.1X49-D170, 17.3 prior to 17.3R3-S7, 17.4 prior to 17.4R2-S8 and 17.4R3, 18.1 prior to 18.1R3-S8, 18.2 prior to 18.2R3, 18.3 prior to 18.3R2, and 18.4 prior to 18.4R2. This widespread impact across multiple release lines indicates a fundamental flaw in the packet forwarding architecture that required patching across different software branches. The vulnerability's presence in these versions suggests that the issue was not properly addressed during the development lifecycle, potentially indicating gaps in testing procedures under high traffic load conditions.
Mitigation strategies for CVE-2019-0050 should prioritize immediate patch application to affected Junos OS versions, with particular attention to the specific release numbers mentioned in the vulnerability advisory. Organizations should implement traffic shaping and rate limiting policies to prevent the conditions that trigger the vulnerability, particularly in high-traffic network segments. Network monitoring solutions should be enhanced to detect srxpfe process crashes and automatically trigger alerts for rapid response. The implementation of redundant firewall systems or failover mechanisms can provide resilience against single points of failure. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network disruption through resource exhaustion attacks, and T1566.002, which addresses phishing attacks that could be used to amplify traffic loads to trigger the vulnerability. Security teams should also consider implementing intrusion detection systems that can identify patterns of traffic that may lead to triggering this vulnerability, enabling proactive mitigation measures before complete service disruption occurs.