CVE-2022-22153 in Junos OS
Summary
by MITRE • 01/19/2022
An Insufficient Algorithmic Complexity combined with an Allocation of Resources Without Limits or Throttling vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series and MX Series with SPC3 allows an unauthenticated network attacker to cause latency in transit packet processing and even packet loss. If transit traffic includes a significant percentage (> 5%) of fragmented packets which need to be reassembled, high latency or packet drops might be observed. This issue affects Juniper Networks Junos OS on SRX Series, MX Series with SPC3: All versions prior to 18.2R3; 18.3 versions prior to 18.3R3; 18.4 versions prior to 18.4R2-S9, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2.
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Analysis
by VulDB Data Team • 01/20/2022
The vulnerability identified as CVE-2022-22153 represents a critical weakness in Juniper Networks Junos OS affecting SRX Series and MX Series devices equipped with SPC3 hardware. This issue stems from insufficient algorithmic complexity combined with uncontrolled resource allocation within the flow processing daemon known as flowd. The flaw manifests when the system processes transit packet traffic, particularly when fragmented packets requiring reassembly constitute more than five percent of the total traffic load. The vulnerability operates at the network processing level where the flowd daemon fails to properly throttle or limit resource consumption during packet reassembly operations, creating a potential denial of service condition that impacts network performance and reliability.
The technical implementation of this vulnerability involves the flowd daemon's handling of fragmented IP packets that must be reassembled before forwarding. When network traffic contains a significant percentage of fragmented packets exceeding the 5% threshold, the daemon's algorithmic complexity proves inadequate to manage the computational requirements of reassembly operations without proper resource limitations. This insufficient complexity means that the system does not implement appropriate rate limiting or resource allocation controls that would prevent excessive CPU and memory consumption during packet reassembly. The vulnerability is classified under CWE-770, which addresses allocation of resources without limits or throttling, and represents a classic example of how inadequate resource management can lead to system degradation and potential service disruption.
The operational impact of this vulnerability extends beyond simple performance degradation to potentially causing complete packet loss and significant network latency issues. Network administrators may observe increasing delays in packet forwarding, intermittent connectivity problems, and ultimately complete service disruption when attack traffic exceeds the threshold conditions. The affected devices operate within critical network infrastructure, making this vulnerability particularly dangerous as it can impact security appliances and routing equipment that form the backbone of network connectivity and traffic management. The vulnerability affects multiple Junos OS versions across different release branches, indicating a widespread issue that requires immediate attention from network operators maintaining affected systems.
Mitigation strategies for CVE-2022-22153 should prioritize applying the relevant security patches provided by Juniper Networks, specifically targeting the affected Junos OS versions mentioned in the advisory. Network administrators should implement traffic filtering mechanisms to reduce the percentage of fragmented packets entering the affected systems, particularly focusing on limiting the volume of fragmented traffic that requires reassembly. The implementation of rate limiting policies on packet reassembly operations and the configuration of appropriate resource allocation limits within the flowd daemon can help prevent exploitation of this vulnerability. Additionally, monitoring systems should be enhanced to detect unusual patterns in packet fragmentation rates and reassembly operations, providing early warning capabilities for potential exploitation attempts. Organizations should also consider implementing network segmentation and traffic shaping policies to reduce the attack surface and limit the potential impact of successful exploitation attempts. The vulnerability demonstrates the importance of proper algorithmic complexity assessment and resource management in network processing daemons, aligning with ATT&CK technique T1499.004 for network denial of service attacks and emphasizing the need for robust resource management controls in network infrastructure software implementations.