CVE-2000-0146 is a medium severity vulnerability affecting the Java Server component of the Novell GroupWise Web Access Enhancement Pack version 5.5. This vulnerability allows remote attackers to cause a denial of service (DoS) condition by sending a specially crafted long URL to the servlet. The root cause is improper handling of excessively long URLs, which leads to resource exhaustion or server instability, effectively disrupting the availability of the GroupWise Web Access service. The vulnerability does not impact confidentiality or integrity, and no authentication is required to exploit it. The attack vector is network-based, and the attacker only needs to send a malicious HTTP request to trigger the DoS. No patches or fixes are available, and there are no known exploits in the wild. Given the age of the vulnerability (published in 2000) and the specific affected product version, exploitation today would depend on the continued use of this legacy software in operational environments.

For European organizations still running Novell GroupWise 5.5 with the Web Access Enhancement Pack, this vulnerability poses a risk of service disruption. A successful DoS attack could render the GroupWise web access interface unavailable, impacting business communications and collaboration. This could be particularly damaging for organizations relying heavily on GroupWise for email and calendaring services, such as government agencies, educational institutions, and enterprises with legacy IT infrastructure. Although the vulnerability does not compromise data confidentiality or integrity, the loss of availability can lead to operational delays, reduced productivity, and potential reputational damage. Since no patch is available, organizations must rely on alternative mitigation strategies to prevent exploitation.

Given the absence of an official patch, European organizations should consider the following specific mitigation measures: 1) Implement network-level protections such as web application firewalls (WAFs) or intrusion prevention systems (IPS) configured to detect and block abnormally long URLs or malformed HTTP requests targeting the GroupWise servlet. 2) Employ rate limiting and connection throttling on the web server to reduce the risk of resource exhaustion from repeated malicious requests. 3) Isolate or segment the GroupWise Web Access server within the network to limit exposure to untrusted networks, restricting access to trusted users or IP ranges where feasible. 4) Monitor server logs and network traffic for unusual patterns indicative of attempted DoS attacks. 5) Plan for migration or upgrade from legacy GroupWise versions to supported, patched software to eliminate this and other vulnerabilities. 6) If possible, disable the Web Access Enhancement Pack servlet if it is not required for business operations.