How severe is CVE-2021-3416?

CVE-2021-3416 has a CVSS 3.x base score of 6.0, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-3416 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3416?

CVE-2021-3416 primarily affects Redhat Enterprise Linux. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3416?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3416 published?

CVE-2021-3416 was published on 2021-03-18 and last updated on 2026-06-17.

CVE-2021-3416

CVE-2021-3416 is a medium-severity vulnerability in Redhat Enterprise Linux with a CVSS 3.x base score of 6.0. 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-835.

Key facts

Severity: Medium (CVSS 3.x base score 6.0)
CVSS v2: 2.1
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-835
Affected product: Redhat Enterprise Linux
Published: 2021-03-18
Last modified: 2026-06-17

Description

A potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario.

Frequently asked questions

What is CVE-2021-3416?: A potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario.
How severe is CVE-2021-3416?: CVE-2021-3416 has a CVSS 3.x base score of 6.0, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-3416 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3416?: CVE-2021-3416 primarily affects Redhat Enterprise Linux. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3416?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3416 published?: CVE-2021-3416 was published on 2021-03-18 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

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