CVE-2021-0294 Junos OS: QFX5000 Series and EX4600 Series: Enhanced storm control might not work leading to partial Denial of Service
Attackers can cause high CPU usage or packet loss on Juniper switches by sending broadcast packets if enhanced storm control is configured but fails to install.
- 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-2021-0294?
CVE-2021-0294 is a medium-severity denial of service vulnerability in Juniper Junos, published on 15 Jul 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, which only affects the release 18.4R2-S5, where a function is inconsistently implemented on Juniper Networks Junos QFX5000 Series and EX4600 Series, and if "storm-control enhanced" is configured, can lead to the enhanced storm control filter group not be installed. It will cause storm control not to work hence allowing an attacker to cause high CPU usage or packet loss issues by sending a large amount of broadcast or unknown unicast packets arriving the device. This issue affects Juniper Networks QFX5100, QFX5110, QFX5120, QFX5200, QFX5210, EX4600, and EX4650, and QFX5100 with QFX 5e Series image installed. QFX5130 and QFX5220 are not affected from this issue. This issue affects Juniper Networks Junos OS 18.4R2-S5 on QFX5000 Series and EX4600 Series. No other product or platform is affected by this vulnerability.
Weakness: CWE-474
Which versions are affected by CVE-2021-0294?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2021-0294?
No fix has been published for CVE-2021-0294 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-2021-0294 being exploited?
There is no known exploitation of CVE-2021-0294 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-2x7j-733f-cc2j.