How severe is CVE-2020-21574?

CVE-2020-21574 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-21574 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-21574?

CVE-2020-21574 affects C-http Project C-http. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-21574?

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-2020-21574 published?

CVE-2020-21574 was published on 2021-11-02 and last updated on 2026-06-17.

CVE-2020-21574

CVE-2020-21574 is a high-severity vulnerability in C-http Project C-http with a CVSS 3.x base score of 7.5. 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 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: C-http Project C-http
Published: 2021-11-02
Last modified: 2026-06-17

Description

Buffer overflow vulnerability in YotsuyaNight c-http v0.1.0, allows attackers to cause a denial of service via a long url request which is passed to the delimitedread function.

Frequently asked questions

What is CVE-2020-21574?: Buffer overflow vulnerability in YotsuyaNight c-http v0.1.0, allows attackers to cause a denial of service via a long url request which is passed to the delimitedread function.
How severe is CVE-2020-21574?: CVE-2020-21574 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-21574 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-21574?: CVE-2020-21574 affects C-http Project C-http. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-21574?: 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-2020-21574 published?: CVE-2020-21574 was published on 2021-11-02 and last updated on 2026-06-17.

References

https://github.com/YotsuyaNight/c-http/issues/1

Affected products (1)

cpe:2.3:a:c-http_project:c-http:0.1.0:*:*:*:*:*:*:*

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