CVE-2017-2348 in Junos
Summary
by MITRE
The Juniper Enhanced jdhcpd daemon may experience high CPU utilization, or crash and restart upon receipt of an invalid IPv6 UDP packet. Both high CPU utilization and repeated crashes of the jdhcpd daemon can result in a denial of service as DHCP service is interrupted. No other Juniper Networks products or platforms are affected by this issue. Affected releases are Juniper Networks Junos OS 14.1X53 prior to 14.1X53-D12, 14.1X53-D38, 14.1X53-D40 on QFX, EX, QFabric System; 15.1 prior to 15.1F2-S18, 15.1R4 on all products and platforms; 15.1X49 prior to 15.1X49-D80 on SRX; 15.1X53 prior to 15.1X53-D51, 15.1X53-D60 on NFX, QFX, EX.
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Analysis
by VulDB Data Team • 01/01/2021
The vulnerability identified as CVE-2017-2348 affects the Juniper Enhanced jdhcpd daemon, which operates as a critical component within Juniper Networks Junos OS implementations. This daemon handles dynamic host configuration protocol operations for ipv6 networks and represents a core service that facilitates network device communication and address assignment. The flaw manifests when the daemon receives malformed ipv6 udp packets, creating a condition that can lead to system instability and service interruption. The vulnerability specifically targets the processing logic within the dhcp daemon without affecting other network services or platforms, indicating a contained scope of impact within the juniper network infrastructure ecosystem.
The technical implementation of this vulnerability stems from inadequate input validation within the jdhcpd daemon's packet processing routines. When the daemon encounters an invalid ipv6 udp packet structure, the parsing logic fails to properly handle the malformed data, resulting in either excessive cpu resource consumption or complete daemon termination. This processing failure creates a recursive condition where the daemon attempts to handle the malformed packet repeatedly, consuming cpu cycles or triggering restart sequences that can cascade into system instability. The vulnerability operates at the network protocol level and demonstrates poor error handling practices that violate fundamental security principles for network services.
The operational impact of this vulnerability extends beyond simple service disruption to create potential denial of service conditions that can severely impact network availability. When the jdhcpd daemon experiences high cpu utilization, network devices lose their ability to dynamically assign ip addresses, effectively breaking dhcp functionality for ipv6 networks. Repeated daemon crashes create additional instability where the service may restart continuously, leading to extended periods of unavailability. This affects network infrastructure components including qfx, ex, qfabric systems, srx platforms, and nfx devices, all of which depend on dhcp services for proper network operation. The vulnerability's impact is particularly concerning because dhcp services are fundamental to network connectivity and device management within enterprise and service provider environments.
Mitigation strategies for CVE-2017-2348 should prioritize immediate software updates to affected junos os versions, specifically implementing the vendor-provided patches for releases 14.1X53-D12, 14.1X53-D38, 14.1X53-D40, 15.1F2-S18, 15.1R4, 15.1X49-D80, 15.1X53-D51, and 15.1X53-D60. Network administrators should also implement network segmentation and access control measures to limit exposure to potentially malicious packets, particularly on ipv6 enabled networks where the vulnerability is most prevalent. Monitoring systems should be configured to detect unusual cpu utilization patterns or daemon restart activity that may indicate exploitation attempts. The vulnerability aligns with CWE-129 and CWE-20 categories related to input validation and improper error handling, and represents a typical attack vector categorized under ATT&CK technique T1499 for network denial of service attacks. Organizations should also consider implementing network intrusion detection systems to identify and block malformed ipv6 udp traffic patterns that could exploit this vulnerability.