How severe is CVE-2021-20721?

CVE-2021-20721 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20721 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20721?

CVE-2021-20721 affects Kujirahand Konawiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20721?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-20721 published?

CVE-2021-20721 was published on 2021-05-20 and last updated on 2026-06-17.

CVE-2021-20721

CVE-2021-20721 is a critical-severity vulnerability in Kujirahand Konawiki with a CVSS 3.x base score of 9.8. 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-434.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Kujirahand Konawiki
Published: 2021-05-20
Last modified: 2026-06-17

Description

KonaWiki2 versions prior to 2.2.4 allows a remote attacker to upload arbitrary files via unspecified vectors. If the file contains PHP scripts, arbitrary code may be executed.

Frequently asked questions

What is CVE-2021-20721?: KonaWiki2 versions prior to 2.2.4 allows a remote attacker to upload arbitrary files via unspecified vectors. If the file contains PHP scripts, arbitrary code may be executed.
How severe is CVE-2021-20721?: CVE-2021-20721 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20721 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20721?: CVE-2021-20721 affects Kujirahand Konawiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20721?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-20721 published?: CVE-2021-20721 was published on 2021-05-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:kujirahand:konawiki:*:*:*:*:*:*:*:*

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