How severe is CVE-2021-20658?

CVE-2021-20658 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20658 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20658?

CVE-2021-20658 affects Contec Sv-cpt-mc310 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20658?

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

When was CVE-2021-20658 published?

CVE-2021-20658 was published on 2021-02-24 and last updated on 2026-06-17.

CVE-2021-20658

CVE-2021-20658 is a critical-severity vulnerability in Contec Sv-cpt-mc310 Firmware with a CVSS 3.x base score of 9.8. 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-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Contec Sv-cpt-mc310 Firmware
Published: 2021-02-24
Last modified: 2026-06-17

Description

SolarView Compact SV-CPT-MC310 prior to Ver.6.5 allows an attacker to execute arbitrary OS commands with the web server privilege via unspecified vectors.

Frequently asked questions

What is CVE-2021-20658?: SolarView Compact SV-CPT-MC310 prior to Ver.6.5 allows an attacker to execute arbitrary OS commands with the web server privilege via unspecified vectors.
How severe is CVE-2021-20658?: CVE-2021-20658 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20658 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20658?: CVE-2021-20658 affects Contec Sv-cpt-mc310 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20658?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-20658 published?: CVE-2021-20658 was published on 2021-02-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:contec:sv-cpt-mc310_firmware:*:*:*:*:*:*:*:*

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