How severe is CVE-2021-47157?

CVE-2021-47157 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-2021-47157 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47157?

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.

Does CVE-2021-47157 have an EU (EUVD) identifier?

Yes. CVE-2021-47157 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33805.

When was CVE-2021-47157 published?

CVE-2021-47157 was published on 2024-03-18 and last updated on 2026-06-17.

CVE-2021-47157

CVE-2021-47157 is a critical-severity vulnerability 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-346.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-33805
Weakness: CWE-346
Published: 2024-03-18
Last modified: 2026-06-17

Description

The Kossy module before 0.60 for Perl allows JSON hijacking because of X-Requested-With mishandling.

Frequently asked questions

What is CVE-2021-47157?: The Kossy module before 0.60 for Perl allows JSON hijacking because of X-Requested-With mishandling.
How severe is CVE-2021-47157?: CVE-2021-47157 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-2021-47157 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47157?: 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.
Does CVE-2021-47157 have an EU (EUVD) identifier?: Yes. CVE-2021-47157 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33805.
When was CVE-2021-47157 published?: CVE-2021-47157 was published on 2024-03-18 and last updated on 2026-06-17.

References

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