How severe is CVE-2020-20021?

CVE-2020-20021 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-20021 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-20021?

CVE-2020-20021 affects Mikrotik Routeros. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-20021?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-20021 published?

CVE-2020-20021 was published on 2023-07-12 and last updated on 2026-07-05.

CVE-2020-20021

CVE-2020-20021 is a high-severity vulnerability in Mikrotik Routeros with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Mikrotik Routeros
Published: 2023-07-12
Last modified: 2026-07-05

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.

Frequently asked questions

What is CVE-2020-20021?: An issue discovered in MikroTik Router v6.46.3 and earlier allows attacker to cause denial of service via misconfiguration in the SSH daemon.
How severe is CVE-2020-20021?: CVE-2020-20021 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-20021 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-20021?: CVE-2020-20021 affects Mikrotik Routeros. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-20021?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-20021 published?: CVE-2020-20021 was published on 2023-07-12 and last updated on 2026-07-05.

References

Affected products (1)

cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*

More vulnerabilities in Mikrotik Routeros

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CVE-2023-30799 — Critical (CVSS 9.1): MikroTik RouterOS stable before 6.49.7 and long-term through 6.48.6 are vulnerable to a privilege escalation issue. A…
CVE-2018-14847 — Critical (CVSS 9.1): MikroTik RouterOS through 6.42 allows unauthenticated remote attackers to read arbitrary files and remote authenticated…
CVE-2022-45313 — High (CVSS 8.8): Mikrotik RouterOs before stable v7.5 was discovered to contain an out-of-bounds read in the hotspot process. This…

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Browse all CWE-400 (Uncontrolled Resource Consumption) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

35.130.111.146 (ipv4-addr)
35.130.111.98 (ipv4-addr)
27.110.176.222 (ipv4-addr)
102.64.43.181 (ipv4-addr)