CVE-2000-1117 in Lotus Notes
Summary
by MITRE
The Extended Control List (ECL) feature of the Java Virtual Machine (JVM) in Lotus Notes Client R5 allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
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Analysis
by VulDB Data Team • 04/07/2019
The vulnerability described in CVE-2000-1117 represents a significant information disclosure flaw within the Lotus Notes Client R5 software that leverages the Java Virtual Machine's Extended Control List functionality. This weakness enables remote attackers to perform timing attacks against client systems by exploiting the behavior of the getSystemResource method, which exhibits different execution delays depending on whether requested resources exist locally on the client machine. The vulnerability specifically affects the Java runtime environment integrated into the Lotus Notes R5 client, creating a covert channel through which malicious actors can infer the presence or absence of specific files within the client's file system.
The technical implementation of this vulnerability stems from the inconsistent response timing characteristics of the JVM's resource retrieval mechanism when processing requests for system resources. When a malicious web page attempts to access a resource that exists on the client system, the getSystemResource method executes more quickly than when attempting to access a non-existent resource, as the JVM can immediately locate and return the existing file. Conversely, when requesting a non-existent resource, the JVM must perform additional search operations and potentially generate error handling delays, resulting in measurable time differences that can be exploited by attackers. This timing differential provides a reliable means of determining file existence without direct file access or content retrieval.
The operational impact of this vulnerability extends beyond simple file enumeration, as it creates a potential pathway for attackers to map the client's file system structure and potentially identify sensitive files or system components. An attacker could systematically test various resource paths and measure response times to build a comprehensive inventory of files present on the target system, which could then be used to plan more sophisticated attacks or identify potential targets for further exploitation. The vulnerability particularly affects organizations using Lotus Notes R5 clients in environments where security is paramount, as it allows unauthorized discovery of local file structures that might contain confidential information or system configuration details.
This vulnerability aligns with CWE-203, Information Exposure Through Timing Discrepancies, and demonstrates characteristics consistent with timing attack methodologies documented in the ATT&CK framework under technique T1082, System Information Discovery. The flaw represents a classic example of how seemingly benign API behaviors can be weaponized when combined with precise timing measurements and network-based attack vectors. Organizations should implement mitigations including updating to supported versions of Lotus Notes, disabling the problematic ECL functionality, or implementing network-level controls to prevent access to potentially malicious web content that could exploit this timing-based information disclosure mechanism.
The security implications of this vulnerability highlight the importance of careful API design and the potential risks associated with exposing timing characteristics in security-sensitive applications. Modern security practices emphasize the need for constant-time operations and consistent response behaviors to prevent timing-based attacks, as demonstrated by the evolution of cryptographic libraries and security protocols that have moved away from variable-time implementations. This vulnerability serves as a historical example of how early Java security implementations in enterprise applications could be undermined by subtle timing characteristics that were not properly considered during the security design phase.