How severe is CVE-2021-31227?

CVE-2021-31227 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-2021-31227 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-2021-31227?

CVE-2021-31227 affects Hcc-embedded Nichestack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-31227?

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-2021-31227 published?

CVE-2021-31227 was published on 2021-08-19 and last updated on 2026-06-17.

CVE-2021-31227

CVE-2021-31227 is a high-severity vulnerability in Hcc-embedded Nichestack 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-787.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Hcc-embedded Nichestack
Published: 2021-08-19
Last modified: 2026-06-17

Description

An issue was discovered in HCC embedded InterNiche 4.0.1. A potential heap buffer overflow exists in the code that parses the HTTP POST request, due to an incorrect signed integer comparison. This vulnerability requires the attacker to send a malformed HTTP packet with a negative Content-Length, which bypasses the size checks and results in a large heap overflow in the wbs_multidata buffer copy.

Frequently asked questions

What is CVE-2021-31227?: An issue was discovered in HCC embedded InterNiche 4.0.1. A potential heap buffer overflow exists in the code that parses the HTTP POST request, due to an incorrect signed integer comparison. This vulnerability requires the attacker to send a malformed HTTP packet with a negative Content-Length, which bypasses the size checks and results in a large heap overflow in the wbs_multidata buffer copy.
How severe is CVE-2021-31227?: CVE-2021-31227 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-2021-31227 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-2021-31227?: CVE-2021-31227 affects Hcc-embedded Nichestack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-31227?: 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-2021-31227 published?: CVE-2021-31227 was published on 2021-08-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:hcc-embedded:nichestack:*:*:*:*:*:*:*:*

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