CVE-2025-53830 Overview
CVE-2025-53830 is a Server-Side Request Forgery (SSRF) vulnerability affecting the Anti-Virus application for ownCloud. The flaw exists in versions of Anti-Virus for ownCloud prior to 1.2.3, corresponding to ownCloud 10 releases before 10.15.3. An authenticated attacker with high privileges can abuse the anti-virus scanning workflow to force the server to issue arbitrary outbound requests. The vulnerability is tracked under CWE-918: Server-Side Request Forgery and can result in confidentiality, integrity, and availability impact across trust boundaries.
Critical Impact
Attackers can pivot from the ownCloud server to reach internal network services, cloud metadata endpoints, and other resources not directly accessible from the public network.
Affected Products
- Anti-Virus for ownCloud versions prior to 1.2.3
- ownCloud 10 versions prior to 10.15.3
- Deployments running the Anti-Virus app against external ICAP or scanning endpoints
Discovery Timeline
- 2026-07-06 - CVE-2025-53830 published to NVD
- 2026-07-08 - Last updated in NVD database
Technical Details for CVE-2025-53830
Vulnerability Analysis
The Anti-Virus application for ownCloud integrates external scanning services to inspect uploaded files before they are stored or shared. The affected versions do not adequately validate or restrict the destination of outbound requests made by the scanning workflow. An authenticated user with sufficient privileges can influence the scan target, causing the server to connect to attacker-chosen hosts and ports.
Because the impact scope changes across a security boundary, an exploited request originates from the trusted ownCloud host and can reach internal resources. This includes internal HTTP services, cloud provider metadata endpoints, and databases that rely on network position for access control.
Root Cause
The root cause is insufficient input validation on URLs and network destinations consumed by the anti-virus scanning logic (CWE-918). The application accepts destinations that resolve to internal, loopback, or link-local addresses without applying an allowlist or DNS rebinding protection. The fix in Anti-Virus for ownCloud 1.2.3 and ownCloud 10.15.3 constrains these outbound requests.
Attack Vector
The attack vector is network-based and requires an authenticated session with high privileges. An attacker configures or triggers the anti-virus scanning path to point at an internal URL such as a metadata service, an internal admin console, or a service reachable only from the ownCloud host. The server issues the request on the attacker's behalf and may return response data, headers, or timing signals that enable further reconnaissance. Chained with other weaknesses, SSRF can expose credentials, tokens, or cloud IAM roles bound to the ownCloud instance.
Refer to the ownCloud GitHub Security Advisory GHSA-3wg4-mg27-hj4w for authoritative technical detail.
Detection Methods for CVE-2025-53830
Indicators of Compromise
- Outbound HTTP or ICAP connections from the ownCloud application server to internal RFC1918, loopback, or link-local addresses.
- Requests from ownCloud to cloud metadata endpoints such as 169.254.169.254.
- Anomalous entries in Anti-Virus app logs showing scan targets that do not match the configured scanning host.
- Unexpected DNS lookups for internal hostnames originating from the ownCloud PHP worker processes.
Detection Strategies
- Monitor egress traffic from ownCloud hosts and alert on connections to internal ranges that were not previously observed.
- Correlate ownCloud audit logs with web proxy or firewall logs to identify scan requests directed at non-approved destinations.
- Inspect Anti-Virus app configuration changes and file upload events performed by privileged accounts.
Monitoring Recommendations
- Enforce egress filtering on the ownCloud server and log all denied outbound requests for review.
- Alert on any HTTP response codes returned to the ownCloud process from cloud metadata IP addresses.
- Review administrative activity on the Anti-Virus app configuration, including changes to scanner URLs.
How to Mitigate CVE-2025-53830
Immediate Actions Required
- Upgrade ownCloud 10 to version 10.15.3 or later.
- Upgrade the Anti-Virus for ownCloud app to version 1.2.3 or later.
- Rotate any credentials, API tokens, or cloud IAM role sessions that were reachable from the ownCloud host during the exposure window.
- Restrict administrative access to the Anti-Virus configuration to a minimal set of accounts.
Patch Information
The vendor has published fixed releases. Apply Anti-Virus for ownCloud 1.2.3 or newer, and ensure the underlying ownCloud 10 platform is on 10.15.3 or newer. Full remediation guidance is available in the ownCloud GitHub Security Advisory GHSA-3wg4-mg27-hj4w.
Workarounds
- Block outbound network access from the ownCloud application server to internal subnets, loopback, and cloud metadata IP addresses at the host firewall or network layer.
- Force the Anti-Virus app to route only to an approved scanning host by enforcing an egress allowlist.
- Disable the Anti-Virus app until patched versions can be deployed if immediate upgrade is not possible.
- On cloud deployments, require IMDSv2 or an equivalent session-based metadata service to reduce the value of any successful SSRF request.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
