Directory StudioApplication · Apache
CVE-2021-33900
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 · uneditedWhile investigating DIRSTUDIO-1219 it was noticed that configured StartTLS encryption was not applied when any SASL authentication mechanism (DIGEST-MD5, GSSAPI) was used. While investigating DIRSTUDIO-1220 it was noticed that any configured SASL confidentiality layer was not applied. This issue affects Apache Directory Studio version 2.0.0.v20210213-M16 and prior versions.
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 · high confidenceIn Apache Directory Studio, when SASL authentication mechanisms (DIGEST-MD5, GSSAPI) are used, the configured StartTLS encryption is silently ignored, allowing connections to proceed without encryption. Additionally, any configured SASL confidentiality layer is never applied. This causes encrypted connections to fail silently, transmitting authentication credentials and data in cleartext despite user expectations of encryption.
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
Directory StudioApplication
<= 1.5.3= 2.0.0CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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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Check Apache Directory Studio versionLocate the Apache Directory Studio installation and check the version number (typically in the application name or readme, e.g., ApacheDirectoryStudio-1.5.3 or ApacheDirectoryStudio-2.0.0)Affected if Version is 1.5.3 or lower, or exactly 2.0.0
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Identify configured LDAP connectionsOpen the Connections view in Apache Directory Studio to list all saved LDAP connection configurationsAffected if Any connection exists in the configuration
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Verify SASL authentication is configuredFor each LDAP connection, open connection settings and inspect the Authentication method or SASL settings. Look for DIGEST-MD5 or GSSAPI selected as the SASL mechanismAffected if Any connection uses DIGEST-MD5 or GSSAPI authentication
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Check if StartTLS is enabled on SASL connectionsIn the connection settings for each SASL-configured connection, examine the Network Layer or Security settings to determine if StartTLS is enabledAffected if StartTLS is enabled on a connection that also uses DIGEST-MD5 or GSSAPI authentication (this is the vulnerable combination)
A user is affected if they use Apache Directory Studio version 1.5.3 or lower (or version 2.0.0) with a connection that combines SASL authentication (DIGEST-MD5 or GSSAPI) together with StartTLS encryption enabled.
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 dataAvoid using SASL authentication (DIGEST-MD5, GSSAPI) with StartTLS until a patch is available; consider using simple authentication with StartTLS or alternative LDAPs (LDAPS) connections instead.
Fix this in Directory Studio
Scoped from the published advisory
- Consultation2.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,960.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33900 — 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-2021-33900 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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- Version or environment caveats, and links to real fixes
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