CVE-2020-1605 in Junos
Summary
by MITRE
When a device using Juniper Network's Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv4 packets who may then arbitrarily execute commands as root on the target device. This issue affects IPv4 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/24/2024
The vulnerability identified as CVE-2020-1605 represents a critical remote code execution flaw within Juniper Networks' Dynamic Host Configuration Protocol Daemon (JDHCPD) implementation running on Junos OS and Junos OS Evolved systems configured in relay mode. This vulnerability stems from insufficient input validation and sanitization within the DHCP processing pipeline, creating a pathway for malicious actors to exploit the system through crafted IPv4 packets. The flaw specifically targets devices operating in relay mode where JDHCPD acts as an intermediary between clients and upstream DHCP servers, making it particularly dangerous in network environments where DHCP relaying is commonly implemented.
The technical exploitation of this vulnerability occurs when an attacker sends specially crafted IPv4 packets to a vulnerable JDHCPD service, triggering a buffer overflow or memory corruption condition that allows arbitrary code execution with root privileges. This represents a severe privilege escalation vulnerability that bypasses normal authentication and authorization mechanisms, enabling attackers to gain complete control over the affected device. The vulnerability affects multiple versions of Junos OS across different release branches, with specific patch levels required to remediate the issue. The attack vector is particularly concerning because it requires minimal privileges to initiate and can be executed remotely without prior authentication, making it highly attractive to threat actors seeking persistent access to network infrastructure.
The operational impact of this vulnerability extends beyond simple device compromise, as it can enable attackers to establish persistent backdoors, exfiltrate sensitive network information, or use the compromised device as a launching point for further attacks within the network perimeter. Organizations relying on Juniper devices configured in DHCP relay mode face significant risk of network infiltration, potentially leading to complete network compromise and data breaches. The vulnerability affects both legacy Junos OS versions and newer Junos OS Evolved deployments, indicating a widespread exposure across Juniper's product portfolio. The fact that this issue does not affect devices operating in non-relay mode or older versions prior to 15.1 provides some limited mitigation scope, but the broad version compatibility of the vulnerability means that most production networks remain at risk.
Security practitioners should implement immediate mitigations including applying the relevant Juniper security patches, disabling DHCP relay functionality where possible, and implementing network segmentation to limit the attack surface. The vulnerability aligns with CWE-121, which describes buffer overflow conditions, and maps to ATT&CK technique T1059.007 for remote code execution, with potential lateral movement opportunities through compromised network devices. Organizations should also consider implementing network monitoring to detect anomalous DHCP traffic patterns that might indicate exploitation attempts, and conduct thorough vulnerability assessments across all Juniper devices to identify unpatched systems. The remediation process requires careful planning due to the critical nature of DHCP services and the potential for service disruption during patch application, making coordinated deployment across network infrastructure essential for effective mitigation.