CVE-2021-0233 Denial of service in Junos OS
An attacker can cause a denial of service on Juniper ACX routers by sending high-rate specific packets, crashing the forwarding engine.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-0233?
CVE-2021-0233 is a high-severity denial of service vulnerability in Juniper Junos, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in Juniper Networks Junos OS ACX500 Series, ACX4000 Series, may allow an attacker to cause a Denial of Service (DoS) by sending a high rate of specific packets to the device, resulting in a Forwarding Engine Board (FFEB) crash. Continued receipt of these packets will sustain the Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS on ACX500 Series, ACX4000 Series: 17.4 versions prior to 17.4R3-S2.
Which versions are affected by CVE-2021-0233?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2021-0233?
No fix has been published for CVE-2021-0233 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-2021-0233 being exploited?
There is no known exploitation of CVE-2021-0233 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-h524-gfx3-m768.