// CVE

CVE-2023-49105

Critical 9.8 Exploited (KEV)

ownCloud ownCloud

9.8CVSS
43%EPSS
YesCISA KEV

Summary

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 bec…

Published: 2023-11-21 · In KEV since: 2026-08-27

Analysis

🔴 Critical — actively exploited

Weakness: Improper Authentication (CWE-287). Allows impersonation or login bypass.

How it's exploited: Exploitable over the network (internet-reachable), unauthenticated, no user interaction, and with low complexity.

⚠️ Critical combo: remote, unauthenticated and no interaction → trivial to automate.

Impact: Full compromise (confidentiality, integrity and availability).

Status: Active exploitation confirmed by CISA (KEV).

How to defend:
  • Patch now: it is in CISA's actively-exploited catalog (KEV), with a deadline.
  • Reduce exposure: keep it off the internet; firewall, VPN or network segmentation.
  • Detect: turn this CVE into detection rules.

MITRE ATT&CK technique: T1190 · Exploit Public-Facing Application

Practice it in the arsenal: WAF Bypass

CVSS vector

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

The vector encodes how it's exploited (translated above, in the analysis). Break it down in the CVSS tool →

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Sources: CISA KEV · EPSS · FIRST.org · NVD. Analysis derived from the CVSS vector and exploitation status (no AI). Informational; always verify against the vendor's official advisory.