CVE-2021-39433Public exploitNetwork attack vector

Arbitrary file disclosure via unchecked download path

Published Oct 4, 2021 · Updated Aug 4, 2024

Path traversal in BIQS IT Biqs-drive 1.83 and earlier allows remote attackers to read arbitrary server files via the download file parameter. The download/index.php handler accepts traversal sequences in the file query parameter and returns the resolved local file without confining the path. No authentication or user interaction is required, and disclosure is limited to files readable by the configured web-user.

CVSS severity7.5
High
EPSS probability8.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in BIQS IT Biqs-drive 1.83 and earlier allows remote attackers to read arbitrary server files via the download file parameter. The download/index.php handler accepts traversal sequences in the file query parameter and returns the resolved local file without confining the path. No authentication or user interaction is required, and disclosure is limited to files readable by the configured web-user.

The record

CVE
CVE-2021-39433
Published
Oct 4, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 4, 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

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

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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 exploitPublished

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

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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