CVE-2006-0118 in Lotus Notes
Summary
by MITRE
Unspecified vulnerability in IBM Lotus Notes and Domino Server before 6.5.5, when running on AIX, allows attackers to cause a denial of service (deep recursion leading to stack overflow and crash) via long formulas.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 11/30/2016
The vulnerability identified as CVE-2006-0118 represents a critical denial of service weakness affecting IBM Lotus Notes and Domino Server versions prior to 6.5.5 when deployed on AIX operating systems. This issue stems from inadequate input validation mechanisms within the formula processing engine of the software, creating a scenario where malformed or excessively long formula expressions can trigger system instability. The vulnerability specifically manifests when the system attempts to process formulas that contain deeply nested recursive structures, leading to uncontrolled stack consumption that ultimately results in system crashes and complete service unavailability.
The technical flaw underlying this vulnerability resides in the absence of proper recursion depth limits and stack space management within the Lotus Notes and Domino Server formula interpreter. When processing a formula containing excessive nesting levels, the system's call stack becomes exhausted through deep recursion patterns that are not adequately monitored or constrained. This behavior aligns with CWE-674, which describes insufficient control of recursion depth, and represents a classic stack overflow condition that occurs when the program's execution stack exceeds its allocated memory space. The vulnerability operates at the application layer, specifically targeting the formula evaluation subsystem that handles various scripting and calculation operations within the Domino environment.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited by malicious actors to systematically degrade system availability and compromise business continuity. Attackers can construct specially crafted formulas containing thousands of nested operations that, when processed by the vulnerable server, will cause the system to crash repeatedly. This creates a persistent denial of service condition that can be difficult to mitigate without immediate patching, as the crash occurs at the system level rather than through network-based attacks. The vulnerability affects the core functionality of Domino Server, which serves as the foundation for email, collaboration, and workflow applications within many enterprise environments, making it particularly dangerous for organizations relying on these services.
Organizations affected by this vulnerability should implement immediate mitigations including applying the official IBM security patches released for versions 6.5.5 and later, which include enhanced recursion detection and stack overflow protection mechanisms. Network segmentation and access controls should be implemented to limit exposure of vulnerable servers to untrusted networks, while monitoring systems should be deployed to detect anomalous formula processing patterns that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1499.004 - Endpoint Denial of Service, as it targets the availability of endpoint systems through application-level exploitation. Additionally, implementing input validation policies and restricting formula complexity through administrative controls can provide additional defense-in-depth measures. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of older software versions that may still be running within the environment, ensuring comprehensive protection against similar recursive exploitation patterns.