Actively exploited · Published Nov 21, 2023 · Assigned by mitre
CVE-2023-49105
Critical 9.8 Exploited
In plain English
A critical-severity improper authentication in ownCloud from ownCloud. Attackers are actively exploiting it in the wild (listed by CISA on August 27, 2026). The chance it is exploited in the next 30 days is estimated at 43.2% (higher than 99% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. 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 guidance
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.
Federal agencies must remediate by Aug 30, 2026.
Official 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.
Affected products (as reported)
Weakness: CWE-287 · Vector: CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N
References
- https://owncloud.org/security
- https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/
- https://hunt.io/blog/chinese-speaking-operator-philippine-nuclear-naval-contractor third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-49105 government-resource