CVE-2020-1681 Junos OS Evolved: Receipt of a specifically malformed NDP packet could lead to Denial of Service
Attackers can cause a denial of service in Junos OS Evolved by sending malformed NDP packets, crashing the ndp process.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-1681?
CVE-2020-1681 is a medium-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 16 Oct 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Receipt of a specifically malformed NDP packet sent from the local area network (LAN) to a device running Juniper Networks Junos OS Evolved can cause the ndp process to crash, resulting in a Denial of Service (DoS). The process automatically restarts without intervention, but a continuous receipt of the malformed NDP packets could leaded to an extended Denial of Service condition. During this time, IPv6 neighbor learning will be affected. The issue occurs when parsing the incoming malformed NDP packet. Rather than simply discarding the packet, the process asserts, performing a controlled exit and restart, thereby avoiding any chance of an unhandled exception. Exploitation of this vulnerability is limited to a temporary denial of service, and cannot be leveraged to cause additional impact on the system. This issue is limited to the processing of IPv6 NDP packets. IPv4 packet processing cannot trigger, and is unaffected by this vulnerability. This issue affects all Juniper Networks Junos OS Evolved versions prior to 20.1R2-EVO. Junos OS is unaffected by this vulnerability.
Which versions are affected by CVE-2020-1681?
It affects 1 product.
Products include Juniper Junos Os Evolved.
How do I fix CVE-2020-1681?
No fix has been published for CVE-2020-1681 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-1681 being exploited?
There is no known exploitation of CVE-2020-1681 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos Os Evolved
- CVE-2026-21902 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
- CVE-2023-28983 Junos OS Evolved: Shell Injection vulnerability in the gNOI server
- CVE-2025-21599 Denial of service in Junos OS Evolved
- CVE-2024-47502 Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS
- CVE-2024-39531 Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols
Sources
Also known as GHSA-w8cp-6x5g-mf2j.