CVE-2020-20021 Denial of service in n/a
An attacker can cause a denial of service on MikroTik routers by exploiting a misconfiguration in the SSH daemon.
- 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-2020-20021?
CVE-2020-20021 is a high-severity denial of service vulnerability in Mikrotik Routeros, published on 12 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue discovered in MikroTik Router v6.46.3 and earlier allows attacker to cause denial of service via misconfiguration in the SSH daemon.
Weakness: CWE-400
Which versions are affected by CVE-2020-20021?
It affects 1 product.
Products include Mikrotik Routeros.
How do I fix CVE-2020-20021?
No fix has been published for CVE-2020-20021 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-2020-20021 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-20021 exists.
Other vulnerabilities in Mikrotik Routeros
- CVE-2018-7445 MikroTik RouterOS Stack-Based Buffer Overflow
- CVE-2026-86060 MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command
- CVE-2018-14847 MikroTik Router OS Directory Traversal
- CVE-2026-67277 MikroTik RouterOS Missing Authentication for Critical Function
- CVE-2026-67279 Mikrotik RouterOS Improper Enforcement of Behavioral Workflow
Sources
Also known as GHSA-x6pw-rqmx-w72p.