CVE-2020-36249Network attack vector

Unauthorized file uploads via public-share filter bypass

Published Feb 19, 2021 · Updated Aug 4, 2024

Improper file-type filtering in ownCloud File Firewall before 2.8.0 allows remote attackers to upload disallowed files to public shares. The public-share upload path fails to apply the firewall's file-type detection, so prohibited types pass when a folder share permits uploads. Exploitation requires an upload-enabled public folder share, and the bounded impact is unauthorized file creation rather than data disclosure or service interruption.

CVSS severity7.5
High
EPSS probability0.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper file-type filtering in ownCloud File Firewall before 2.8.0 allows remote attackers to upload disallowed files to public shares. The public-share upload path fails to apply the firewall's file-type detection, so prohibited types pass when a folder share permits uploads. Exploitation requires an upload-enabled public folder share, and the bounded impact is unauthorized file creation rather than data disclosure or service interruption.

The record

CVE
CVE-2020-36249
Published
Feb 19, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-791, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 19, 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

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

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-791Incomplete Filtering of Special Elements
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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