How severe is CVE-2021-27198?

CVE-2021-27198 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-2021-27198 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27198?

CVE-2021-27198 affects Visualware Myconnection Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27198?

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-2021-27198 published?

CVE-2021-27198 was published on 2021-02-26 and last updated on 2026-06-17.

CVE-2021-27198

CVE-2021-27198 is a critical-severity vulnerability in Visualware Myconnection Server with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 14% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-434.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 14% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Visualware Myconnection Server
Published: 2021-02-26
Last modified: 2026-06-17

Description

An issue was discovered in Visualware MyConnection Server before v11.1a. Unauthenticated Remote Code Execution can occur via Arbitrary File Upload in the web service when using a myspeed/sf?filename= URI. This application is written in Java and is thus cross-platform. The Windows installation runs as SYSTEM, which means that exploitation gives one Administrator privileges on the target system.

Frequently asked questions

What is CVE-2021-27198?: An issue was discovered in Visualware MyConnection Server before v11.1a. Unauthenticated Remote Code Execution can occur via Arbitrary File Upload in the web service when using a myspeed/sf?filename= URI. This application is written in Java and is thus cross-platform. The Windows installation runs as SYSTEM, which means that exploitation gives one Administrator privileges on the target system.
How severe is CVE-2021-27198?: CVE-2021-27198 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-2021-27198 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27198?: CVE-2021-27198 affects Visualware Myconnection Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27198?: 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-2021-27198 published?: CVE-2021-27198 was published on 2021-02-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:visualware:myconnection_server:*:*:*:*:*:*:*:*

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