How severe is CVE-2020-16843?

CVE-2020-16843 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-16843 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-16843?

CVE-2020-16843 primarily affects Amazon Firecracker. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-16843?

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

When was CVE-2020-16843 published?

CVE-2020-16843 was published on 2020-08-04 and last updated on 2026-06-17.

CVE-2020-16843

CVE-2020-16843 is a medium-severity vulnerability in Amazon Firecracker with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Amazon Firecracker
Published: 2020-08-04
Last modified: 2026-06-17

Description

In Firecracker 0.20.x before 0.20.1 and 0.21.x before 0.21.2, the network stack can freeze under heavy ingress traffic. This can result in a denial of service on the microVM when it is configured with a single network interface, and an availability problem for the microVM network interface on which the issue is triggered.

Frequently asked questions

What is CVE-2020-16843?: In Firecracker 0.20.x before 0.20.1 and 0.21.x before 0.21.2, the network stack can freeze under heavy ingress traffic. This can result in a denial of service on the microVM when it is configured with a single network interface, and an availability problem for the microVM network interface on which the issue is triggered.
How severe is CVE-2020-16843?: CVE-2020-16843 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-16843 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-16843?: CVE-2020-16843 primarily affects Amazon Firecracker. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-16843?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-16843 published?: CVE-2020-16843 was published on 2020-08-04 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:amazon:firecracker:0.20.0:*:*:*:*:*:*:*
cpe:2.3:a:amazon:firecracker:0.21.0:*:*:*:*:*:*:*
cpe:2.3:a:amazon:firecracker:0.21.1:*:*:*:*:*:*:*

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