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CISA Known Exploited Vulnerabilities

ownCloud Improper Authentication Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV
2026-08-27
Remediation due
2026-08-30

Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

CISA notes
https://owncloud.org/security ; https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2023-49105

Description

An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.

Severity

CVSS 3.1 · CNA9.8 CRITICAL
CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N
SSVC · CISA-ADP
Exploitationactive
Automatableyes
Technical impacttotal

Affected Products

VendorProductAffected versions
--
n/a

References

2 Links

Record Details

Published
2023-11-21
Last updated
2026-08-28
Assigner (CNA)
mitre
Credited to
-

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.