CVE-2021-33895Network attack vector

Installer SUPER access via fail-open password validation

Published Jun 25, 2021 · Updated Aug 4, 2024

Improper authentication in ETINET BackBox E4.09 and H4.09 allows remote attackers to access the UI by supplying the BBSV process user ID. USER_AUTHENTICATE_ returns zero when that ID is not running XYGate, and BBSV incorrectly treats the result as successful password verification. Knowledge of the BBSV process user ID is required, and successful exploitation grants Installer SUPER access through the BackBox UI.

CVSS severity8.1
High
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in ETINET BackBox E4.09 and H4.09 allows remote attackers to access the UI by supplying the BBSV process user ID. USER_AUTHENTICATE_ returns zero when that ID is not running XYGate, and BBSV incorrectly treats the result as successful password verification. Knowledge of the BBSV process user ID is required, and successful exploitation grants Installer SUPER access through the BackBox UI.

The record

CVE
CVE-2021-33895
Published
Jun 25, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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