CVE-2023-49105
ownCloud — ownCloud Improper Authentication Vulnerability
ownCloud · CWE-287 — Improper authentication · in CISA KEV since 2026-08-27
EVRS 76 of 100 Urgent
Patch This Cycle
Rank 687 of 2,954 tracked
Why it scores 76
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.432.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyApplied
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
- owncloud.org/…/security
- owncloud.com/…/webdav-api-authentication-bypass-using-pre-signed-urls
- BOD 26-04
- Forensics Triage Requirements
- nvd.nist.gov/…/CVE-2023-49105
Fixed in
owncloud server: update to 10.13.1 or later
Affected versions
- owncloud server
>= 10.6.0 < 10.13.1
Remediation
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.
Fixed versions from NVD.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 9.8 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.432 (98.7th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2026-08-30 · CISA federal deadline · Overdue by 54 days | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | None known | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 9.8 (v3.1), assigned by mitre. | Listed | ENISA EUVD |
Description
NVDAn 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.
What CISA says to do
