How severe is CVE-2021-42357?

CVE-2021-42357 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-42357 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42357?

CVE-2021-42357 affects Apache Knox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42357?

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

When was CVE-2021-42357 published?

CVE-2021-42357 was published on 2022-01-17 and last updated on 2026-06-17.

CVE-2021-42357

CVE-2021-42357 is a medium-severity vulnerability in Apache Knox with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Apache Knox
Published: 2022-01-17
Last modified: 2026-06-17

Description

When using Apache Knox SSO prior to 1.6.1, a request could be crafted to redirect a user to a malicious page due to improper URL parsing. A request that included a specially crafted request parameter could be used to redirect the user to a page controlled by an attacker. This URL would need to be presented to the user outside the normal request flow through a XSS or phishing campaign.

Frequently asked questions

What is CVE-2021-42357?: When using Apache Knox SSO prior to 1.6.1, a request could be crafted to redirect a user to a malicious page due to improper URL parsing. A request that included a specially crafted request parameter could be used to redirect the user to a page controlled by an attacker. This URL would need to be presented to the user outside the normal request flow through a XSS or phishing campaign.
How severe is CVE-2021-42357?: CVE-2021-42357 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-42357 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42357?: CVE-2021-42357 affects Apache Knox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42357?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-42357 published?: CVE-2021-42357 was published on 2022-01-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apache:knox:*:*:*:*:*:*:*:*

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