CVE-1999-0776 is a directory traversal vulnerability affecting version 2.0 of the Alibaba HTTP server, a web server software developed by computer_software_manufaktur. This vulnerability allows remote attackers to read arbitrary files on the server by exploiting a '..' (dot dot) attack, which manipulates the file path to traverse directories outside the intended web root. The vulnerability does not require authentication and can be exploited over the network with low attack complexity. The impact is limited to confidentiality, allowing attackers to access sensitive files, but it does not affect integrity or availability. No patches are available for this vulnerability, and no known exploits have been reported in the wild. Given the age of the vulnerability (published in 1999) and the specific affected product version, the risk today depends on whether legacy systems still run this software. The CVSS score is 5.0 (medium severity), reflecting the ease of exploitation and the confidentiality impact without affecting system integrity or availability.

For European organizations, the primary risk is unauthorized disclosure of sensitive information stored on servers running Alibaba HTTP server version 2.0. This could include configuration files, credentials, or proprietary data, potentially leading to further compromise or data breaches. However, given the age of the vulnerability and the lack of patches or known exploits, it is likely that this software is no longer widely used in production environments. Organizations still operating legacy systems with this server are at risk, especially if these servers are internet-facing. The confidentiality breach could have regulatory implications under GDPR if personal data is exposed. The impact on operational continuity is minimal since the vulnerability does not allow modification or denial of service.

Since no official patches are available, European organizations should prioritize decommissioning or upgrading any systems running Alibaba HTTP server version 2.0. If immediate replacement is not feasible, network-level controls such as firewall rules should restrict external access to the affected servers. Implementing web application firewalls (WAFs) with rules to detect and block directory traversal attempts can provide additional protection. Regularly auditing server configurations and file permissions to minimize sensitive data exposure is critical. Organizations should also monitor logs for suspicious access patterns indicative of directory traversal attempts. Finally, migrating to modern, supported web server software with active security maintenance is strongly recommended to eliminate this and other legacy vulnerabilities.