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.
Conclusion & alert: CVE-2023-49105 is rated High Risk (74.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 89.61%, 100th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-12-22 | 89.27% | 89.61% | +0.33% |
| 2 | 2025-12-09 | 88.87% | 89.27% | +0.40% |
| 3 | 2025-12-08 | — | 88.87% | — |
Full EPSS history (42 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
ubuntu
|
medium | CVE-2023-49105 medium priority: Ubuntu including 1 source packages (owncloud), 8 status rows across 8 suites (bionic, focal, jammy, lunar, mantic, trusty, upstream, xenial): DNE 4, ignored 3, needs-triage 1. | https://ubuntu.com/security/CVE-2023-49105 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| owncloud | owncloud_server | >= 10.6.0, < 10.13.1 | cpe:2.3:a:owncloud:owncloud_server:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/ | Vendor Advisory |
| https://owncloud.org/security | Product |