CVE-2022-28981 is a path traversal vulnerability identified in the Hypermedia REST APIs module of Liferay Portal versions 7.4.0 through 7.4.2. This vulnerability allows remote attackers to exploit the 'parameter' parameter to access files outside the intended directory scope, specifically outside of the com.liferay.headless.discovery.web/META-INF/resources directory. Path traversal (CWE-22) vulnerabilities occur when user-supplied input is not properly sanitized, enabling attackers to manipulate file paths and access arbitrary files on the server's filesystem. In this case, the vulnerability is remotely exploitable without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The CVSS score of 7.5 (high severity) reflects the significant confidentiality impact, as attackers can read sensitive files, but no integrity or availability impact is noted. Although no known exploits are currently reported in the wild, the ease of exploitation and the potential to access sensitive configuration or data files pose a serious risk. Liferay Portal is a widely used enterprise web platform for building portals and websites, often deployed in corporate and public sector environments. The vulnerability could allow attackers to access sensitive information such as configuration files, credentials, or other protected resources, potentially leading to further compromise or data leakage.

For European organizations, the impact of CVE-2022-28981 can be substantial, especially for those relying on Liferay Portal for critical web services, intranet portals, or customer-facing applications. Unauthorized access to sensitive files could expose confidential business data, user information, or internal configurations, leading to data breaches and compliance violations under regulations such as GDPR. The confidentiality breach could also facilitate lateral movement within networks or enable attackers to craft more sophisticated attacks. Since the vulnerability does not require authentication, any exposed Liferay Portal instance accessible over the internet is at risk, increasing the attack surface. Public sector organizations, financial institutions, and large enterprises in Europe that use Liferay Portal may face reputational damage and operational disruptions if exploited. Additionally, the lack of known patches or mitigations at the time of publication increases the urgency for organizations to implement compensating controls.

To mitigate CVE-2022-28981, European organizations should first verify if they are running affected versions of Liferay Portal (7.4.0 to 7.4.2) and prioritize upgrading to a fixed version once available from the vendor. Until patches are released, organizations should implement strict network-level access controls to restrict access to the Liferay Portal REST API endpoints, especially the Hypermedia REST APIs module. Deploying Web Application Firewalls (WAFs) with custom rules to detect and block path traversal patterns in the 'parameter' parameter can provide temporary protection. Additionally, conducting thorough input validation and sanitization on all user-supplied parameters in custom Liferay modules can reduce risk. Monitoring logs for unusual file access attempts and scanning for exposed sensitive files on the server can help detect exploitation attempts early. Organizations should also review and minimize file permissions on the server to limit the impact of any unauthorized file access. Finally, maintaining an incident response plan that includes this vulnerability scenario will improve readiness in case of exploitation.