How severe is CVE-2021-42979?

CVE-2021-42979 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42979 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42979?

CVE-2021-42979 affects Nomachine Cloud Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42979?

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-2021-42979 published?

CVE-2021-42979 was published on 2021-12-07 and last updated on 2026-06-17.

CVE-2021-42979

CVE-2021-42979 is a high-severity vulnerability in Nomachine Cloud Server with a CVSS 3.x base score of 8.8. 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-190.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Nomachine Cloud Server
Published: 2021-12-07
Last modified: 2026-06-17

Description

NoMachine Cloud Server is affected by Integer Overflow. IOCTL Handler 0x22001B in the NoMachine Cloud Server above 4.0.346 and below 7.7.4 allow local attackers to execute arbitrary code in kernel mode or cause a denial of service (memory corruption and OS crash) via specially crafted I/O Request Packet.

Frequently asked questions

What is CVE-2021-42979?: NoMachine Cloud Server is affected by Integer Overflow. IOCTL Handler 0x22001B in the NoMachine Cloud Server above 4.0.346 and below 7.7.4 allow local attackers to execute arbitrary code in kernel mode or cause a denial of service (memory corruption and OS crash) via specially crafted I/O Request Packet.
How severe is CVE-2021-42979?: CVE-2021-42979 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42979 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42979?: CVE-2021-42979 affects Nomachine Cloud Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42979?: 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-2021-42979 published?: CVE-2021-42979 was published on 2021-12-07 and last updated on 2026-06-17.

References

https://www.sentinelone.com/labs/usb-over-ethernet-multiple-privilege-escalation-vulnerabilities-in-aws-and-other-major-cloud-services/

Affected products (1)

cpe:2.3:a:nomachine:cloud_server:*:*:*:*:*:*:*:*

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