CVE-2023-49105: ownCloud Improper Authentication Vulnerability

Summary

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.

Remediation

Inventory every ownCloud ownCloud deployment, including staging.
No fixed version appears in the public sources yet. Check the references below and the vendor directly.
Review logs from before the change for signs of exploitation.

CISA required actionApply 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.

References

Advisoryhttps://owncloud.org/security
Advisoryhttps://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/
Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
Advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2023-49105
Advisoryhttps://hunt.io/blog/chinese-speaking-operator-philippine-nuclear-naval-contractor
Referencehttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-49105