How severe is CVE-2021-32976?

CVE-2021-32976 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-2021-32976 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-32976?

CVE-2021-32976 primarily affects Moxa Nport Iaw5150a-6i/o Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-32976?

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-2021-32976 published?

CVE-2021-32976 was published on 2022-04-01 and last updated on 2026-06-17.

CVE-2021-32976

CVE-2021-32976 is a critical-severity vulnerability in Moxa Nport Iaw5150a-6i/o Firmware 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Moxa Nport Iaw5150a-6i/o Firmware
Published: 2022-04-01
Last modified: 2026-06-17

Description

Five buffer overflows in the built-in web server in Moxa NPort IAW5000A-I/O series firmware version 2.2 or earlier may allow a remote attacker to initiate a denial-of-service attack and execute arbitrary code.

Frequently asked questions

What is CVE-2021-32976?: Five buffer overflows in the built-in web server in Moxa NPort IAW5000A-I/O series firmware version 2.2 or earlier may allow a remote attacker to initiate a denial-of-service attack and execute arbitrary code.
How severe is CVE-2021-32976?: CVE-2021-32976 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-2021-32976 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-32976?: CVE-2021-32976 primarily affects Moxa Nport Iaw5150a-6i/o Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-32976?: 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-2021-32976 published?: CVE-2021-32976 was published on 2022-04-01 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:moxa:nport_iaw5150a-6i\/o_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:moxa:nport_iaw5150a-12i\/o_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:moxa:nport_iaw5250a-6i\/o_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:moxa:nport_iaw5250a-12i\/o_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Moxa Nport Iaw5150a-6i/o Firmware

CVE-2021-32974 — Critical (CVSS 9.8): Improper input validation in the built-in web server in Moxa NPort IAW5000A-I/O series firmware version 2.2 or earlier…
CVE-2021-32970 — High (CVSS 7.5): Data can be copied without validation in the built-in web server in Moxa NPort IAW5000A-I/O series firmware version 2.2…
CVE-2021-32968 — High (CVSS 7.5): Two buffer overflows in the built-in web server in Moxa NPort IAW5000A-I/O Series firmware version 2.2 or earlier may…

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