HOME VULNERABILITIESCVE-2021-33828

HIGH

CVE-2021-33828

CWE-434Published: January 15, 2022· Updated: Jun 17, 2026

8.8

CVSS v3.1

Official Description

The files_antivirus component before 1.0.0 for ownCloud mishandles the protection mechanism by which malicious files (that have been uploaded to a public share) are supposed to be deleted upon detection.

Technical Analysis

CVE-2021-33828 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.Low

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

owncloud1 product(s)

files antivirus

Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://doc.owncloud.com/server/admin_manual/release_notes.html

ADVISORYhttps://owncloud.com/security-advisories/cve-2021-33828/

ADVISORYhttps://doc.owncloud.com/server/admin_manual/release_notes.html

ADVISORYhttps://owncloud.com/security-advisories/cve-2021-33828/

All References (4)

→

https://doc.owncloud.com/server/admin_manual/release_notes.htmlRelease Notes · Vendor Advisory

→

https://owncloud.com/security-advisories/cve-2021-33828/Vendor Advisory

→

https://doc.owncloud.com/server/admin_manual/release_notes.htmlRelease Notes · Vendor Advisory

→

https://owncloud.com/security-advisories/cve-2021-33828/Vendor Advisory

Quick Facts

CVE IDCVE-2021-33828

CVSS Score8.8 / 10

SeverityHIGH

WeaknessCWE-434

CISA KEVNo

Affected1 vendor(s)

PublishedJan 15, 2022

Related CVEs (CWE-434)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2021-33828 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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