How severe is CVE-2021-43225?

CVE-2021-43225 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 high, integrity none, and availability none.

Is CVE-2021-43225 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43225?

CVE-2021-43225 affects Microsoft Bot Framework Software Development Kit. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43225?

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-2021-43225 published?

CVE-2021-43225 was published on 2021-12-15 and last updated on 2026-06-17.

CVE-2021-43225

CVE-2021-43225 is a high-severity vulnerability in Microsoft Bot Framework Software Development Kit 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.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.5
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Bot Framework Software Development Kit
Published: 2021-12-15
Last modified: 2026-06-17

Description

Bot Framework SDK Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2021-43225?: Bot Framework SDK Remote Code Execution Vulnerability
How severe is CVE-2021-43225?: CVE-2021-43225 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 high, integrity none, and availability none.
Is CVE-2021-43225 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43225?: CVE-2021-43225 affects Microsoft Bot Framework Software Development Kit. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43225?: 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-2021-43225 published?: CVE-2021-43225 was published on 2021-12-15 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43225

Affected products (1)

cpe:2.3:a:microsoft:bot_framework_software_development_kit:-:*:*:*:*:.net_framework:*:*

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