CVE-2009-0366 in Wesnoth
Summary
by MITRE
The uncompress_buffer function in src/server/simple_wml.cpp in Wesnoth before r33069 allows remote attackers to cause a denial of service via a large compressed WML document.
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Analysis
by VulDB Data Team • 08/30/2019
The vulnerability identified as CVE-2009-0366 affects the Wesnoth game engine version prior to r33069, specifically within the uncompress_buffer function located in src/server/simple_wml.cpp. This flaw represents a classic denial of service vulnerability that exploits the game's handling of compressed WML (Wesnoth Markup Language) documents during server operations. The vulnerability arises from insufficient input validation and buffer management when processing compressed data streams, creating a scenario where maliciously crafted compressed documents can trigger unexpected behavior in the server's decompression routines.
The technical implementation of this vulnerability stems from the function's failure to properly validate the size and structure of compressed WML data before attempting decompression operations. When a remote attacker sends a large compressed WML document to the Wesnoth server, the uncompress_buffer function processes this input without adequate bounds checking or resource allocation limits. This leads to potential buffer overflows or excessive memory consumption that can cause the server to crash or become unresponsive, effectively denying service to legitimate users. The vulnerability operates at the application layer and can be exploited through network connections to the game server, making it particularly dangerous in multiplayer gaming environments where server stability is crucial.
From an operational perspective, this vulnerability significantly impacts the availability and reliability of Wesnoth servers, especially those hosting multiplayer games or community events. The denial of service condition can be triggered by any remote user with network access to the server, requiring minimal technical expertise to exploit successfully. The impact extends beyond simple service interruption as it can disrupt gaming sessions, affect community engagement, and potentially damage the reputation of server administrators who rely on stable gaming platforms. The vulnerability's exploitation does not require authentication or elevated privileges, making it particularly concerning for public game servers that are accessible to anyone on the internet.
The vulnerability aligns with CWE-129, which describes improper validation of length parameters, and CWE-121, which addresses stack-based buffer overflow conditions. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service attacks, and T1566.002, which involves spearphishing with social engineering techniques that could be used to deliver malicious compressed documents. Mitigation strategies should focus on implementing proper input validation and size limits for compressed data, adding resource monitoring to detect abnormal memory usage patterns, and applying the security patch released with Wesnoth version r33069. Additionally, network-level protections such as rate limiting and connection monitoring can help detect and prevent exploitation attempts before they can cause service disruption.