CVE-2021-43394
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUnisys 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceUnisys OS 2200 Messaging Integration Services (NTSI) versions 7R3B IC3/IC4, 7R3C, and 7R3D contain an incorrect implementation of the authentication algorithm that fails to properly validate LDAP passwords, allowing attackers to potentially bypass authentication mechanisms.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 7r3b_ic3= 7r3b_ic4= 7r3c= 7r3dCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify NTSI version installedUse Unisys system management commands or check the Messaging Integration Services version information. On the OS 2200 system, use 'VERS' or equivalent command to display installed software versions, specifically looking for 'NTSI' or 'Messaging Integration Services' with version number.Affected if The installed version matches exactly 7r3b_ic3, 7r3b_ic4, 7r3c, or 7r3d
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Verify LDAP authentication is configuredExamine the NTSI configuration files or system parameters that define authentication settings. Look for LDAP-related configuration entries in the NTSI configuration directory or system registry where authentication method is specified.Affected if LDAP is configured as the authentication mechanism for NTSI user authentication
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Confirm NTSI service is activeCheck if the Messaging Integration Services (NTSI) daemon or service is running on the system using system status commands like 'SHOW SYSTEM' or 'STATUS NTSI' on the OS 2200 platform.Affected if The NTSI service is running and accepting authentication requests
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Review LDAP bind configurationInspect the NTSI authentication configuration to verify how LDAP bind operations are performed. Check whether the LDAP bind is configured to properly validate credentials against the LDAP directory, or if a fallback or bypass mechanism exists.Affected if LDAP bind is configured but password validation may be bypassed or incorrectly implemented
You are affected if NTSI version is exactly 7r3b_ic3, 7r3b_ic4, 7r3c, or 7r3d AND LDAP authentication is enabled for the Messaging Integration Services.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement proper LDAP password validation within the NTSI authentication logic, and ensure the LDAP bind process correctly verifies credentials before granting access. Consider restricting LDAP authentication to secure channels and validating user inputs.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,776.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-43394 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-43394 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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