CVE-2006-1998 in OpenTTD
Summary
by MITRE
OpenTTD 0.4.7 and earlier allows local users to cause a denial of service (application exit) via a large invalid error number, which triggers an error.
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Analysis
by VulDB Data Team • 04/10/2025
The vulnerability identified as CVE-2006-1998 affects OpenTTD version 0.4.7 and earlier, representing a denial of service flaw that can be exploited by local users through the manipulation of error handling mechanisms within the application. This vulnerability specifically targets the game engine's error reporting system where improper validation of error numbers leads to application instability and potential termination. The flaw occurs when the software encounters an invalid error number that exceeds the acceptable range for error handling, causing the application to crash and exit unexpectedly.
The technical implementation of this vulnerability resides in the error management subsystem of OpenTTD, where the software fails to properly validate input parameters before processing them as error codes. This represents a classic case of inadequate input validation and error handling, which falls under the CWE-20 category of "Improper Input Validation" and the CWE-707 category of "Improper Neutralization of Special Elements used in a Command." The vulnerability manifests when a local attacker provides a large invalid error number that triggers an unhandled exception or buffer overflow condition within the error processing routines, leading to the application's abrupt termination.
From an operational perspective, this vulnerability presents a significant risk to system availability and user experience within gaming environments where OpenTTD is deployed. Local users can exploit this flaw to disrupt gameplay sessions and potentially cause system instability, particularly in multi-user environments where the application might be running continuously. The impact extends beyond simple service disruption as the application's termination could result in loss of unsaved game progress and potential data corruption. The vulnerability's local nature means that exploitation requires physical access to the system or the ability to execute code locally, but this still represents a serious security concern for any system where OpenTTD is installed.
The exploitation of this vulnerability aligns with ATT&CK technique T1499.004 "Endpoint Denial of Service" and demonstrates the importance of robust error handling in software applications. Mitigation strategies should focus on implementing proper input validation for error numbers, establishing bounds checking mechanisms, and implementing graceful error recovery procedures. System administrators should prioritize updating to OpenTTD versions that address this vulnerability, as well as implementing monitoring solutions to detect unusual application termination patterns. Additionally, application hardening measures such as stack protection and address space layout randomization can provide additional defense in depth against similar exploitation vectors. The vulnerability serves as a reminder of the critical importance of proper error handling in preventing denial of service conditions, particularly in applications that handle user-generated content or external inputs.