CVE-2021-33895
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 · uneditedETINET BACKBOX E4.09 and H4.09 mismanages password access control. When a user uses the User ID of the process running BBSV to login to the Backbox UI application, the system procedure (USER_AUTHENTICATE_) used for verifying the Password returns 0 (no error). The reason is that the user is not running the XYGate application. Hence, BBSV assumes the Password is correct. For H4.09, the affected version isT0954V04^AAO. For E4.09, the affected version is 22SEP2020. Note: If your current version is E4.10-16MAY2021 (version procedure T9999V04_16MAY2022_BPAKETI_10), a hotfix (FIXPAK-19OCT-2022) is available in version E4.10-19OCT2022. Resolution to CVE-2021-33895 in version E4.11-19OCT2022
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 confidenceAuthentication bypass in ETINET BACKBOX E4.09 and H4.09 where the USER_AUTHENTICATE_ system procedure returns success (0) when a user logs in with the User ID of the BBSV process but is not running the XYGate application, allowing password verification to be bypassed.
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= t0954v04\^aao= 2020-09-22CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/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 the Backbox firmware versionCheck the system firmware version in the Backbox administration interface or via system information command. Look for version strings matching 't0954v04^aao' (H4.09) or build date '2020-09-22' (E4.09).Affected if The installed version is H4.09 with firmware t0954v04^aao or E4.09 with firmware dated 2020-09-22.
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Verify if the XYGate application is runningCheck the process list or system status to determine whether the XYGate application is currently active on the Backbox device.Affected if XYGate is not running while authentication attempts are being made using the BBSV process User ID.
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Review USER_AUTHENTICATE_ system procedure behaviorExamine authentication logs or test the USER_AUTHENTICATE_ system procedure with a login attempt using the BBSV process User ID while XYGate is not active, observing if it returns success (0) without proper password validation.Affected if The procedure returns success (0) for BBSV User ID logins when XYGate is not running, bypassing password verification.
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Check authentication logs for anomalous BBSV process loginsReview authentication and audit logs for successful login events where the BBSV process User ID was used without XYGate application being active.Affected if There are successful authentications using BBSV User ID when XYGate was not running.
The environment is affected if running Backbox E4.09 (2020-09-22) or H4.09 (t0954v04^aao) firmware and the USER_AUTHENTICATE_ procedure returns success for BBSV User ID logins when the XYGate application is not running.
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 dataUpgrade to E4.11-19OCT2022 or later, or apply hotfix FIXPAK-19OCT-2022 for E4.10-16MAY2021.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33895 — 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-2021-33895 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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