CVE-2001-1018 in Domino
Summary
by MITRE
Lotus Domino web server 5.08 allows remote attackers to determine the internal IP address of the server when NAT is enabled via a GET request that contains a long sequence of / (slash) characters.
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Analysis
by VulDB Data Team • 09/30/2025
The vulnerability described in CVE-2001-1018 affects IBM Lotus Domino web server version 5.08 and represents a significant information disclosure flaw that can be exploited by remote attackers to uncover internal network infrastructure details. This vulnerability specifically manifests when the web server operates behind a Network Address Translation device, creating a scenario where internal IP addresses could be exposed through seemingly benign web requests. The flaw exploits the server's handling of URL paths that contain an excessive number of forward slash characters, which reveals internal network addressing information that should remain hidden from external parties.
The technical mechanism behind this vulnerability involves the Lotus Domino web server's processing of HTTP GET requests containing elongated sequences of slash characters. When such requests are submitted to the server, the web server's internal path resolution mechanism inadvertently exposes the internal IP address of the system through its response handling or error reporting mechanisms. This occurs because the server's configuration and processing logic do not adequately sanitize or normalize the path components in the URL, allowing the internal network addressing information to leak through the application layer. The vulnerability is classified under CWE-200 Information Exposure, which encompasses weaknesses that lead to unintended information disclosure. This specific variant falls into the category of information leakage through improper error handling or path traversal mechanisms that do not properly validate input parameters.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with crucial network topology information that can be leveraged for further attacks. Knowledge of the internal IP address allows adversaries to conduct more targeted reconnaissance activities, potentially enabling them to map internal network structures and identify other vulnerable systems within the same network segment. This information can facilitate subsequent attacks such as port scanning, service enumeration, or even direct exploitation of internal services that may not be protected by the same security measures as external-facing components. The vulnerability directly relates to ATT&CK technique T1016 Network Service Scanning, as it provides the initial information needed to perform more comprehensive network reconnaissance activities. Additionally, this vulnerability can be combined with other techniques to create a more complete attack vector, as the disclosed IP address may reveal internal network boundaries and potentially expose systems that were intended to be isolated from external access.
Mitigation strategies for this vulnerability should focus on both immediate configuration changes and long-term architectural improvements. The most effective immediate solution involves updating the Lotus Domino web server to a patched version that properly sanitizes URL path components and prevents the exposure of internal addressing information during request processing. Organizations should also implement proper input validation mechanisms that normalize and limit the length of path components in web requests, preventing maliciously crafted URLs from triggering the information disclosure behavior. Network-level mitigations include implementing proper firewall rules that restrict access to internal network information and deploying web application firewalls that can detect and block requests containing suspicious path structures. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in web application security, where internal system information should never be exposed through external interfaces. Organizations should also consider implementing network segmentation strategies to minimize the impact of such information disclosure events and establish monitoring procedures to detect unusual patterns in web server responses that may indicate exploitation attempts.