[UPDATE] [critical] ownCloud: Multiple vulnerabilities
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
A remote, anonymous attacker can exploit multiple vulnerabilities in ownCloud to disclose information, bypass security measures, and manipulate files.
CSIRTS triage
- What
- Multiple vulnerabilities in ownCloud allow remote anonymous attackers to disclose information, bypass security measures, and manipulate files.
- Who is affected
- All ownCloud deployments are affected; exploitation is already active.
- Urgency
- Critical; actively exploited vulnerabilities with remote unauthenticated attack vector.
- Action
- Apply the latest ownCloud security patches immediately and verify file integrity.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2023-2985
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2023-49103Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99.6% of all EPSS-scored CVEs.
- Exploitation confirmedCVE-2023-49105Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2023-491040.56% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 44% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2023-49103 | coverage & exploitation status | NVD · CVE.org |
| CVE-2023-49105 | coverage & exploitation status | NVD · CVE.org |
| CVE-2023-49104 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- highexploitedCISA Adds Three Known Exploited Vulnerabilities to Catalogcisa
- criticalexploitedCVE-2023-49105: ownCloud Improper Authentication Vulnerabilitycisa-kev
- criticalexploitedCVE-2023-49103: ownCloud graphapi Information Disclosure Vulnerabilitycisa-kev
Recent advisories for ownCloud
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- criticalexploitedCVE-2023-49105: ownCloud Improper Authentication Vulnerabilitycisa-kev · 2026-08-27
- highCVE-2025-53831: DrawIO for ownCloud is an application for using DrawIO with the file storage, synchronization,…nvd · 2026-07-06
- criticalCVE-2025-53830: Anti-Virus for ownCloud is an anti-virus application for file storage, synchronization, and sh…nvd · 2026-07-06
- highCVE-2025-53829: ownCloud is a file storage, synchronization, and sharing application. In ownCloud 10 prior to …nvd · 2026-07-06
- highCVE-2025-53828: SharePoint for ownCloud is an application for using SharePoint with the file storage, synchron…nvd · 2026-07-06
- criticalCVE-2025-53827: ownCloud Core is the server-side component of the file storage, synchronization, and sharing a…nvd · 2026-07-06
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