How severe is CVE-2021-42311?

CVE-2021-42311 has a CVSS 3.x base score of 10.0, 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-2021-42311 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42311?

CVE-2021-42311 affects Microsoft Defender For Iot. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42311?

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-2021-42311 published?

CVE-2021-42311 was published on 2021-12-15 and last updated on 2026-06-17.

CVE-2021-42311

CVE-2021-42311 is a critical-severity vulnerability in Microsoft Defender For Iot with a CVSS 3.x base score of 10.0. 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-89.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
CVSS v2: 10.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-89
Affected product: Microsoft Defender For Iot
Published: 2021-12-15
Last modified: 2026-06-17

Description

Microsoft Defender for IoT Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2021-42311?: Microsoft Defender for IoT Remote Code Execution Vulnerability
How severe is CVE-2021-42311?: CVE-2021-42311 has a CVSS 3.x base score of 10.0, 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-2021-42311 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42311?: CVE-2021-42311 affects Microsoft Defender For Iot. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42311?: 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-2021-42311 published?: CVE-2021-42311 was published on 2021-12-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:microsoft:defender_for_iot:*:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Defender For Iot

CVE-2021-42313 — Critical (CVSS 10.0): Microsoft Defender for IoT Remote Code Execution Vulnerability
CVE-2024-38089 — Critical (CVSS 9.1): Microsoft Defender for IoT Elevation of Privilege Vulnerability
CVE-2021-43882 — Critical (CVSS 9.0): Microsoft Defender for IoT Remote Code Execution Vulnerability
CVE-2024-29053 — High (CVSS 8.8): Microsoft Defender for IoT Remote Code Execution Vulnerability
CVE-2024-21323 — High (CVSS 8.8): Microsoft Defender for IoT Remote Code Execution Vulnerability
CVE-2021-42315 — High (CVSS 8.8): Microsoft Defender for IoT Remote Code Execution Vulnerability

All CVEs affecting Microsoft Defender For Iot →

Other CWE-89 (SQL Injection) vulnerabilities

CVE-2026-54350 — Critical (CVSS 10.0): Budibase is an open-source low-code platform. Prior to 3.39.12, an unauthenticated visitor of any published Budibase…
CVE-2026-8054 — Critical (CVSS 10.0): Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') in the Publish Audit API endpoints…
CVE-2026-42287 — Critical (CVSS 10.0): Emlog is an open source website building system. Prior to version 2.6.11, direct SQL injection in article creation and…
CVE-2026-3325 — Critical (CVSS 10.0): SQL injection (SQLi) in MegaCMS v12.0.0, specifically in the “id_territorio” parameter of the…
CVE-2025-10878 — Critical (CVSS 10.0): A SQL injection vulnerability exists in the login functionality of Fikir Odalari AdminPando 1.0.1 before 2026-01-26.…
CVE-2025-57792 — Critical (CVSS 10.0): Explorance Blue versions prior to 8.14.9 contain a SQL injection vulnerability caused by insufficient validation of…

Browse all CWE-89 (SQL Injection) vulnerabilities →