CVE-2021-42973

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-12-07 · updated 2026-06-17
Weakness: CWE-190

Description

NoMachine Server is affected by Integer Overflow. IOCTL Handler 0x22001B in the NoMachine 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.

Affected products

NoMachine Server: from 4.0.346 (excl.) before 7.7.4 — fixed in 7.7.4

How to fix

Upgrade to a fixed version: NoMachine Server 7.7.4. Check the vendor advisory for mitigations.

References

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

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