How severe is CVE-2021-42990?

CVE-2021-42990 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-2021-42990 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42990?

CVE-2021-42990 affects Flexihub. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42990?

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-2021-42990 published?

CVE-2021-42990 was published on 2021-12-07 and last updated on 2026-06-17.

CVE-2021-42990

CVE-2021-42990 is a high-severity vulnerability in Flexihub 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-120.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Flexihub
Published: 2021-12-07
Last modified: 2026-06-17

Description

FlexiHub For Windows is affected by Buffer Overflow. IOCTL Handler 0x22001B in the FlexiHub For Windows above 2.0.4340 below 5.3.14268 allows 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-2021-42990?: FlexiHub For Windows is affected by Buffer Overflow. IOCTL Handler 0x22001B in the FlexiHub For Windows above 2.0.4340 below 5.3.14268 allows 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-2021-42990?: CVE-2021-42990 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-2021-42990 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42990?: CVE-2021-42990 affects Flexihub. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42990?: 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-2021-42990 published?: CVE-2021-42990 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:flexihub:flexihub:*:*:*:*:*:*:*:*

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