How severe is CVE-2021-43394?

CVE-2021-43394 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-2021-43394 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43394?

CVE-2021-43394 primarily affects Unisys Messaging Integration Services. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-43394?

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-2021-43394 published?

CVE-2021-43394 was published on 2022-01-24 and last updated on 2026-06-17.

CVE-2021-43394

CVE-2021-43394 is a critical-severity vulnerability in Unisys Messaging Integration Services 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-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Unisys Messaging Integration Services
Published: 2022-01-24
Last modified: 2026-06-17

Description

Unisys OS 2200 Messaging Integration Services (NTSI) 7R3B IC3 and IC4, 7R3C, and 7R3D has an Incorrect Implementation of an Authentication Algorithm. An LDAP password is not properly validated.

Frequently asked questions

What is CVE-2021-43394?: Unisys OS 2200 Messaging Integration Services (NTSI) 7R3B IC3 and IC4, 7R3C, and 7R3D has an Incorrect Implementation of an Authentication Algorithm. An LDAP password is not properly validated.
How severe is CVE-2021-43394?: CVE-2021-43394 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-2021-43394 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43394?: CVE-2021-43394 primarily affects Unisys Messaging Integration Services. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-43394?: 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-2021-43394 published?: CVE-2021-43394 was published on 2022-01-24 and last updated on 2026-06-17.

References

https://public.support.unisys.com/common/public/vulnerability/NVD_Detail_Rpt.aspx?ID=66

Affected products (4)

cpe:2.3:a:unisys:messaging_integration_services:7r3b_ic3:*:*:*:*:*:*:*
cpe:2.3:a:unisys:messaging_integration_services:7r3b_ic4:*:*:*:*:*:*:*
cpe:2.3:a:unisys:messaging_integration_services:7r3c:*:*:*:*:*:*:*
cpe:2.3:a:unisys:messaging_integration_services:7r3d:*:*:*:*:*:*:*

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