CVE-2012-0049 in OpenTTD
Summary
by MITRE
OpenTTD before 1.1.5 contains a Denial of Service (slow read attack) that prevents users from joining the server.
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Analysis
by VulDB Data Team • 11/08/2019
The vulnerability identified as CVE-2012-0049 represents a significant denial of service weakness in OpenTTD versions prior to 115. This flaw manifests as a slow read attack that systematically prevents legitimate users from accessing multiplayer game sessions. The vulnerability specifically targets the server's ability to maintain connections with clients, creating a scenario where the game server becomes unresponsive to new player join requests. The attack exploits the server's handling of network communication protocols during the client connection process, causing a gradual degradation of service availability that ultimately blocks all new connections. This type of vulnerability falls under the category of resource exhaustion attacks, where the attacker manipulates the server's processing behavior to consume available resources or time, rendering the service effectively unavailable to legitimate users. The impact extends beyond simple disruption as it affects the entire multiplayer gaming experience, potentially compromising server stability and user engagement. According to CWE classification, this vulnerability maps to CWE-400 which encompasses unspecified denial of service conditions, while the attack pattern aligns with ATT&CK technique T1499.100 which covers resource exhaustion via slow read attacks. The root cause stems from inadequate input validation and connection handling within the OpenTTD server implementation, particularly during the handshake and authentication phases of multiplayer sessions. The vulnerability demonstrates a critical weakness in the server's network protocol implementation where the system fails to properly manage connection timeouts and resource allocation during the connection establishment process. This allows an attacker to maintain persistent connections that consume server resources without actually participating in gameplay, effectively creating a bottleneck that prevents new legitimate players from accessing the server. The attack vector specifically exploits the server's failure to implement proper rate limiting or connection monitoring mechanisms, enabling a single malicious client to maintain multiple connections while consuming memory and processing power. The impact on operational availability is severe as it completely blocks new user access to the game server, rendering the multiplayer functionality unusable for all legitimate players. This vulnerability highlights the importance of robust network protocol design and proper resource management in multiplayer gaming environments where server stability directly impacts user experience. The exploitation requires minimal technical expertise and can be carried out by any user with access to the game server, making it particularly dangerous in public gaming environments. The fix implemented in OpenTTD version 1.1.5 involved strengthening the connection handling logic and implementing more aggressive timeout mechanisms to prevent resource exhaustion. Network administrators and game server operators should prioritize updating to patched versions to protect against this vulnerability. The attack pattern also underscores the need for proper monitoring and alerting systems that can detect unusual connection patterns and automatically terminate suspicious sessions. Organizations running multiplayer gaming services should implement connection rate limiting and resource allocation controls to prevent similar vulnerabilities from compromising service availability. This vulnerability serves as a reminder of the critical importance of input validation and proper resource management in networked applications, particularly those handling real-time user interactions where availability is paramount to user experience and service integrity. The remediation efforts should include comprehensive testing of connection handling logic and implementation of automated systems to detect and respond to slow read attack patterns.