CVE-2001-0601 in Domino
Summary
by MITRE
Lotus Domino R5 prior to 5.0.7 allows a remote attacker to create a denial of service via HTTP requests containing certain combinations of UNICODE characters.
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Analysis
by VulDB Data Team • 10/05/2025
The vulnerability identified as CVE-2001-0601 affects IBM Lotus Domino R5 versions prior to 5.0.7, representing a significant security flaw in the web server component that handles HTTP requests. This issue stems from inadequate input validation mechanisms within the Domino server's HTTP processing engine, specifically when handling UNICODE character sequences in web requests. The vulnerability exists at the application layer and can be exploited remotely without requiring authentication, making it particularly dangerous for web-facing servers. The flaw manifests when the server encounters HTTP requests containing specific combinations of UNICODE characters that trigger unexpected behavior in the parsing logic, ultimately leading to system instability and service disruption.
The technical root cause of this vulnerability lies in the improper handling of UNICODE character encoding within the HTTP request processing pipeline of Lotus Domino R5. When the web server receives requests containing certain UNICODE character combinations, the parsing routines fail to properly validate or sanitize these inputs, causing the server to enter an unstable state. This behavior can be categorized under CWE-129, which deals with insufficient validation of length of input buffers, and CWE-20, which addresses improper input validation. The vulnerability specifically impacts the HTTP stack of the Domino server, where UNICODE characters are processed through the web server's request handling mechanisms, leading to memory corruption or resource exhaustion conditions that result in denial of service.
From an operational impact perspective, this vulnerability poses a severe threat to organizations relying on Lotus Domino R5 for their web services and email infrastructure. Remote attackers can exploit this weakness by crafting malicious HTTP requests containing carefully constructed UNICODE character sequences that trigger the denial of service condition. The impact extends beyond simple service interruption as the vulnerability can potentially cause the Domino server process to crash, restart unexpectedly, or consume excessive system resources, effectively rendering the web services unavailable to legitimate users. This type of attack aligns with ATT&CK technique T1499.004, which involves network denial of service attacks targeting web applications. Organizations may experience extended downtime, service degradation, and potential data accessibility issues when this vulnerability is exploited, particularly in environments where Domino servers host critical business applications.
The exploitation of CVE-2001-0601 requires minimal technical expertise and can be accomplished through automated tools that generate malformed HTTP requests with specific UNICODE character combinations. This makes the vulnerability particularly dangerous as it can be leveraged by attackers with limited skills to disrupt services. The vulnerability affects all versions of Lotus Domino R5 prior to 5.0.7, including various patches and service releases that did not address this specific issue. Organizations should implement immediate mitigations including applying the official IBM security patch 5.0.7 or higher, which contains the necessary fixes to properly validate UNICODE character sequences in HTTP requests. Network-level mitigations such as implementing web application firewalls or filtering rules to detect and block suspicious UNICODE character sequences in HTTP requests can provide additional protection. Additionally, monitoring systems should be configured to detect unusual patterns of HTTP requests that may indicate exploitation attempts, and regular security assessments should verify that all Domino servers have been updated to the latest secure versions to prevent this vulnerability from being exploited in production environments.