CVE-2001-0939 in Domino
Summary
by MITRE
Lotus Domino 5.08 and earlier allows remote attackers to cause a denial of service (crash) via a SunRPC NULL command to port 443.
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Analysis
by VulDB Data Team • 05/19/2019
The vulnerability identified as CVE-2001-0939 represents a critical denial of service flaw affecting IBM Lotus Domino versions 5.08 and earlier. This weakness specifically targets the SunRPC implementation within the Domino server software, creating an exploitable condition that can be leveraged by remote attackers to disrupt service availability. The vulnerability manifests when the system receives a malformed SunRPC NULL command directed at the standard HTTPS port 443, which typically serves secure web traffic and is commonly used for Domino web access. The flaw exists within the protocol handling mechanism of the Domino server's RPC subsystem, where insufficient input validation allows maliciously crafted packets to trigger unexpected behavior in the application's processing logic.
The technical nature of this vulnerability stems from the absence of proper boundary checking and input sanitization within the SunRPC service implementation. When the Domino server receives the NULL command, it fails to properly handle the malformed request, leading to memory corruption or stack overflow conditions that ultimately cause the application to crash and terminate its service. This type of vulnerability falls under the category of improper input validation as defined by CWE-20, which specifically addresses weaknesses related to insufficient validation of input data. The flaw represents a classic example of a buffer overflow or memory management error that occurs during network protocol processing, particularly affecting the RPC communication layer that Lotus Domino uses for various internal and external operations.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited remotely without requiring authentication or special privileges from the attacker. The fact that the attack vector targets port 443 makes it particularly dangerous since this port is commonly accessible and often exposed to external networks. Organizations running affected versions of Lotus Domino may experience complete service outages, potentially affecting email services, web applications, and other Domino-dependent systems. The vulnerability's remote exploitability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how a seemingly minor protocol handling flaw can result in significant operational disruption. The impact is particularly severe in enterprise environments where Lotus Domino serves as a critical infrastructure component for business communications and collaboration services.
Organizations affected by this vulnerability should immediately implement mitigations focusing on network segmentation and access control measures. The most effective immediate solution involves blocking access to port 443 from external networks or implementing firewall rules that restrict RPC traffic to trusted internal networks only. Additionally, network monitoring should be enhanced to detect anomalous RPC traffic patterns that might indicate exploitation attempts. The vulnerability's remediation requires upgrading to Lotus Domino versions 5.09 or later, which contain patches addressing the SunRPC handling issues. Security administrators should also consider implementing intrusion detection systems capable of identifying and blocking malformed RPC commands, as well as establishing incident response procedures to quickly address any exploitation attempts. This vulnerability highlights the importance of proper input validation and secure coding practices, particularly in network services that handle external communications, and serves as a reminder of the critical need for regular security updates and vulnerability management processes.