An Uncontrolled Resource Consumption vulnerability in the ARP daemon (arpd) and Network Discovery Protocol (ndp) process of Juniper Networks Junos OS Evolved allows a malicious attacker on the local network to consume memory resources, ultimately resulting in a Denial of Service (DoS) condition. Link-layer functions such as IPv4 and/or IPv6 address resolution may be impacted, leading to traffic loss. The processes do not recover on their own and must be manually restarted. Changes in memory usage can be monitored using the following shell commands (header shown for clarity): user@router:/var/log# ps aux | grep arpd USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 31418 59.0 0.7 *5702564* 247952 ? xxx /usr/sbin/arpd --app-name arpd -I object_select --shared-objects-mode 3 user@router:/var/log# ps aux | grep arpd USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 31418 49.1 1.0 *5813156* 351184 ? xxx /usr/sbin/arpd --app-name arpd -I object_select --shared-objects-mode 3 Memory usage can be monitored for the ndp process in a similar fashion: user@router:/var/log# ps aux | grep ndp USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 14935 0.0 0.1 *5614052* 27256 ? Ssl Jun15 0:17 /usr/sbin/ndp -I no_tab_chk,object_select --app-name ndp --shared-obje user@router:/var/log# ps aux | grep ndp USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 14935 0.0 0.1 *5725164* 27256 ? Ssl Jun15 0:17 /usr/sbin/ndp -I no_tab_chk,object_select --app-name ndp --shared-obje This issue affects Juniper Networks Junos OS Evolved: 19.4 versions prior to 19.4R2-S3-EVO; 20.1 versions prior to 20.1R2-S4-EVO; all versions of 20.2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 19.4R2-EVO.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.5, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 1 product from juniper organizations running these solutions should prioritize assessment and patching.
Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2021-07-15T20:15:11.090
2026-06-17T03:29:44.137
Modified
CVSSv3.1: 6.5 (MEDIUM)
AV:A/AC:L/Au:N/C:N/I:N/A:P
6.5
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | juniper | junos_os_evolved | 19.4 | Yes |
| Operating System | juniper | junos_os_evolved | 19.4 | Yes |
| Operating System | juniper | junos_os_evolved | 19.4 | Yes |
| Operating System | juniper | junos_os_evolved | 19.4 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.1 | Yes |
| Operating System | juniper | junos_os_evolved | 20.2 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For juniper's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.