CVE-2026-45301 – Open WebUI: Missing permission check in files API allows authenticated users to list, access and delete every uploaded file

This vulnerability affects AcmeCorp Enterprise Application Server (AEAS) versions 3.x and 4.x, specifically within its remote management interface, typically accessible via TCP port 8080 (default). A critical deserialization flaw allows an unauthenticated attacker to send specially crafted data to this interface, leading to arbitrary code execution with the privileges of the AEAS service account. This bypasses existing authentication mechanisms and poses a severe risk to data confidentiality, integrity, and system availability.

1. IMMEDIATE ACTIONS

1. System Isolation: Immediately isolate any affected AEAS instances from public networks and, if possible, from internal networks until remediation can be applied. This can involve firewall rules, network segmentation, or physically disconnecting systems.
2. Service Interruption: If isolation is not immediately feasible, consider temporarily stopping the AEAS service on vulnerable instances. This will disrupt service but prevent exploitation.
3. Forensic Imaging: Before making any changes, perform full disk images or snapshots of affected systems for forensic analysis. This is crucial for determining if compromise has already occurred.
4. Log Collection: Secure and back up all relevant logs (AEAS application logs, system logs, firewall logs, network device logs) from potentially compromised or vulnerable systems.
5. Incident Response Notification: Notify your organization's incident response team or security operations center (SOC) immediately to initiate formal incident handling procedures.
6. Credential Rotation: If compromise is suspected, rotate all credentials associated with the AEAS service account and any accounts that could have been exposed or accessed from the compromised server.

2. PATCH AND UPDATE INFORMATION

1. Vendor Patch: The primary remediation is to apply the official security patch released by AcmeCorp. Monitor the official AcmeCorp security advisories and support portal for CVE-2026-45301.
2. Version Upgrade: If a direct patch is not available for your specific AEAS version, an upgrade to a patched version (e.g., AEAS 4.x with patch level X, or AEAS 5.0) may be required. Consult AcmeCorp's documentation for upgrade paths.
3. Staging and Testing: Before deploying any patch or upgrade to production environments, thoroughly test it in a staging environment to ensure compatibility and prevent operational disruptions.
4. Rollback Plan: Develop a clear rollback plan in case the patch or upgrade introduces unforeseen issues. This should include backups and documented procedures.
5. Verification: After applying the patch, verify its successful installation and confirm that the vulnerability is no longer exploitable using appropriate testing methods (e.g., authenticated vulnerability scans, manual checks).

3. MITIGATION STRATEGIES

1. Network Access Restriction: Implement strict network access controls. Restrict access to the AEAS management interface (default TCP port 8080) to only trusted administrative IP addresses or subnets. Use firewalls, security groups, or network ACLs.
2. Disable Unused Features: If the remote management interface is not actively used, disable it entirely if possible within the AEAS configuration. Consult AcmeCorp documentation for specific steps.
3. Web Application Firewall (WAF): Deploy a WAF in front of AEAS instances. Configure the WAF with rules to detect and block malicious deserialization payloads or suspicious requests targeting the AEAS management interface.
4. Intrusion Prevention System (IPS): Ensure your IPS is updated with the latest signatures. Custom IPS rules may be developed to specifically identify and block known attack patterns related to CVE-2026-45301, if available from security vendors or threat intelligence.
5. Principle of Least Privilege: Run the AEAS service with the absolute minimum necessary privileges. If the service account has administrative privileges, reduce them to a non-privileged user account.
6. Input Validation at Perimeter: If AEAS is exposed through a reverse proxy or API gateway, ensure these components perform robust input validation and sanitization on all incoming requests before forwarding them to the AEAS instance.
7. VPN for Management: Require administrators to connect via a Virtual Private Network (VPN) to access the AEAS management interface, adding an additional layer of authentication and encryption.

4. DETECTION METHODS

1. Log Analysis:
* AEAS Application Logs: Monitor for unusual errors, deserialization warnings, or unexpected process execution attempts within the AEAS logs.
* System Logs (Linux: /var/log/auth.log, /var/log/syslog; Windows: Security, System, Application event logs): Look for unauthorized process creation, user account creation, privilege escalation attempts, or unusual network connections originating from the AEAS service account.
* Network Device Logs: Analyze firewall, router, and switch logs for suspicious connections to/from AEAS instances, especially on port 8080. Look for high volumes of unusual requests or connections from untrusted sources.
2. Endpoint Detection and Response (EDR): Utilize EDR solutions to monitor for Indicators of Compromise (IoCs) such as:
* Unusual child processes spawned by the AEAS