CVE-2025-43750 is a medium-severity vulnerability affecting multiple versions of Liferay Portal and Liferay DXP, specifically versions 7.4.0 through 7.4.3.132, and various quarterly releases of Liferay DXP from 2024.Q1.1 through 2025.Q1.1. The vulnerability is classified under CWE-434, which pertains to the unrestricted upload of files with dangerous types. The core issue is that remote unauthenticated users (guests) can upload files through the form attachment field without proper validation. This lack of validation allows attackers to bypass MIME type checks and use extension obfuscation techniques to upload potentially malicious files. Because the upload functionality does not adequately verify the file type or extension, attackers can upload executable or script files disguised with benign extensions or obfuscated names. This can lead to the execution of arbitrary code or scripts on the server, potentially compromising the confidentiality, integrity, and availability of the affected system. The vulnerability requires no authentication and no privileges, but does require some user interaction (uploading a file). The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:A), low impact on confidentiality and integrity (VC:L, VI:L), no impact on availability (VA:N), and low scope change (SC:L). No known exploits are currently reported in the wild, and no patches are linked yet, indicating that organizations should be vigilant and prepare to apply fixes once available.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a significant risk, especially for public-facing web portals that allow guest users to upload files. Successful exploitation could allow attackers to upload malicious files that may lead to remote code execution, data leakage, or defacement of websites. This could disrupt business operations, damage reputation, and lead to regulatory non-compliance, particularly under GDPR if personal data is compromised. The ability for unauthenticated users to upload files increases the attack surface and risk of automated attacks or exploitation by opportunistic threat actors. Organizations relying on Liferay for customer portals, intranets, or digital experience platforms must consider the potential for service disruption and data breaches. The medium severity rating suggests that while the vulnerability is serious, exploitation may require some user interaction and may not lead to full system compromise without additional vulnerabilities or misconfigurations.

1. Immediate mitigation should include restricting or disabling file upload functionality for unauthenticated users until a patch is available. 2. Implement strict server-side validation of uploaded files, including verifying file extensions, MIME types, and scanning files for malware. 3. Employ application-layer firewalls or web application firewalls (WAFs) with rules to detect and block suspicious file uploads or extension obfuscation attempts. 4. Monitor logs for unusual file upload activity and implement alerting for anomalous behavior. 5. Use sandboxing or isolated environments to handle uploaded files, preventing direct execution on production servers. 6. Once available, promptly apply official patches or updates from Liferay addressing this vulnerability. 7. Educate administrators and developers about secure file upload practices and review configurations to minimize exposure. 8. Consider implementing multi-factor authentication and limiting guest user capabilities to reduce attack vectors.