CVE-2023-49105

Product

ownCloud / ownCloud

Vulnerability

ownCloud Improper Authentication Vulnerability

Added to KEV

Aug 27, 2026

Remediate by

Aug 30, 2026

Known ransomware use

No

Summary description

ownCloud contains an improper authentication vulnerability that allows an attacker to access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured.

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.

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