CVE-2017-2301 in Junos
Summary
by MITRE
On Juniper Networks products or platforms running Junos OS 11.4 prior to 11.4R13-S3, 12.1X46 prior to 12.1X46-D60, 12.3 prior to 12.3R12-S2 or 12.3R13, 12.3X48 prior to 12.3X48-D40, 13.2X51 prior to 13.2X51-D40, 13.3 prior to 13.3R10, 14.1 prior to 14.1R8, 14.1X53 prior to 14.1X53-D12 or 14.1X53-D35, 14.1X55 prior to 14.1X55-D35, 14.2 prior to 14.2R7, 15.1 prior to 15.1F6 or 15.1R3, 15.1X49 prior to 15.1X49-D60, 15.1X53 prior to 15.1X53-D30 and DHCPv6 enabled, when a crafted DHCPv6 packet is received from a subscriber, jdhcpd daemon crashes and restarts. Repeated crashes of the jdhcpd process may constitute an extended denial of service condition for subscribers attempting to obtain IPv6 addresses.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/04/2020
The vulnerability described in CVE-2017-2301 represents a critical denial of service weakness in Juniper Networks Junos OS versions prior to specific security patches. This flaw affects multiple major release lines including 11.4, 12.1X46, 12.3, 12.3X48, 13.2X51, 13.3, 14.1, 14.1X53, 14.1X55, 14.2, 15.1, 15.1X49, and 15.1X53, specifically when DHCPv6 functionality is enabled on affected systems. The vulnerability resides within the jdhcpd daemon which is responsible for handling DHCPv6 protocol operations in Juniper network infrastructure devices.
The technical implementation of this vulnerability involves a buffer overflow or memory corruption issue within the jdhcpd daemon's packet processing routine. When the daemon receives a specially crafted DHCPv6 packet from a subscriber, the malformed packet triggers an unexpected behavior in the software's memory management or input validation mechanisms. This typically occurs during the parsing or handling of specific DHCPv6 options or fields that are not properly sanitized or validated by the daemon. The flaw manifests as an immediate crash of the jdhcpd process, causing the daemon to terminate and automatically restart. This crash-restart cycle can be initiated by sending a single malicious packet or by repeating the attack with multiple packets, leading to sustained service disruption.
The operational impact of this vulnerability extends beyond simple service interruption as it creates a persistent denial of service condition for IPv6 address allocation services. Network administrators face significant operational challenges when this vulnerability is exploited since the jdhcpd daemon restarts automatically, making it difficult to determine the root cause of service disruptions. Subscribers attempting to obtain IPv6 addresses through DHCPv6 services experience complete service denial until the affected system is patched or the daemon is manually stopped. The vulnerability affects the core network infrastructure functionality, particularly impacting IPv6 network access and address assignment capabilities in enterprise and service provider environments. Organizations relying on Juniper devices for network infrastructure management face potential business disruption and increased operational overhead during incident response and remediation activities.
The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios, as the daemon crashes indicate memory corruption issues. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, specifically targeting network denial of service through exploitation of service vulnerabilities. The attack surface is particularly concerning as it requires minimal privileges to exploit and can be executed remotely through network traffic. Organizations should implement immediate mitigation strategies including applying the relevant security patches provided by Juniper, implementing network segmentation to isolate vulnerable devices, and monitoring for anomalous DHCPv6 traffic patterns that may indicate exploitation attempts. Additionally, network administrators should consider disabling DHCPv6 functionality on affected devices until patches are applied, and establish monitoring procedures to detect repeated daemon restarts that could indicate exploitation of this vulnerability.