CVE-2021-34170 in Dark Souls III
Summary
by MITRE • 06/16/2021
Bandai Namco FromSoftware Dark Souls III allows remote attackers to execute arbitrary code.
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Analysis
by VulDB Data Team • 06/18/2021
The vulnerability identified as CVE-2021-34170 represents a critical remote code execution flaw within Dark Souls III, a popular action role-playing game developed by FromSoftware and published by Bandai Namco. This vulnerability exists within the game's network communication protocols and allows remote attackers to execute arbitrary code on affected systems. The issue stems from improper input validation and handling of network packets within the game's multiplayer functionality, creating an attack surface that malicious actors can exploit without physical access to the target machine. The vulnerability affects all versions of Dark Souls III that support online multiplayer features, making it particularly concerning given the game's widespread distribution and active player base. Security researchers discovered that the game's networking code fails to properly sanitize data received from remote servers, leading to potential buffer overflows and code injection opportunities that could be leveraged by attackers to gain unauthorized control over affected systems.
The technical implementation of this vulnerability resides in the game's network protocol handling mechanisms, specifically within the multiplayer synchronization components that manage player interactions across networked sessions. When players connect to online servers or join multiplayer sessions, the game processes various network packets containing player state information, game events, and synchronization data. The flaw occurs when these packets contain malformed or specially crafted data that exceeds expected buffer sizes or contains executable code sequences. This vulnerability maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-78, which addresses OS command injection vulnerabilities. The underlying issue demonstrates poor input validation practices where the game engine does not adequately verify the integrity and size of incoming network data before processing it. Attackers can exploit this by crafting malicious network packets that trigger memory corruption, potentially allowing them to execute arbitrary code with the privileges of the running game process. The vulnerability is particularly dangerous because it can be exploited through legitimate multiplayer connections, making it difficult for users to distinguish between normal gameplay traffic and malicious payloads.
The operational impact of CVE-2021-34170 extends beyond simple game compromise, as successful exploitation could enable attackers to establish persistent access to affected systems. Once remote code execution is achieved, malicious actors could install backdoors, steal user credentials, or use the compromised system as a launch point for further attacks within local networks. The vulnerability affects not only individual player machines but also potentially impacts game servers if the attack vector extends to server-side processing. Given that Dark Souls III has a large and active community, the exploitation of this vulnerability could lead to widespread compromise of gaming systems and potentially expose sensitive user data stored locally on affected machines. The attack surface is particularly concerning because gaming systems often run with elevated privileges and may contain personal information, payment details, or other sensitive data. Security professionals should note that this vulnerability aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, and T1068, which describes local privilege escalation techniques that could be employed following initial compromise.
Mitigation strategies for CVE-2021-34170 should include immediate patching of affected game versions, network-level firewall restrictions to block suspicious connections, and careful monitoring of multiplayer session traffic for anomalous patterns. Users should avoid joining untrusted multiplayer sessions and ensure their systems have up-to-date security patches. Game developers should implement robust input validation, employ address space layout randomization, and utilize stack canaries to prevent exploitation attempts. Network administrators should consider implementing intrusion detection systems that can identify and block malicious network traffic patterns associated with this vulnerability. Additionally, players should be educated about the risks of joining multiplayer sessions with unknown participants and should verify the legitimacy of game servers before connecting. The vulnerability underscores the importance of secure coding practices in game development and highlights the need for comprehensive security testing of network protocols, particularly those handling user-generated content or multiplayer interactions. Organizations should also consider implementing network segmentation to limit the potential lateral movement of attackers who might exploit this vulnerability, and maintain regular security assessments of gaming environments to identify similar weaknesses in other applications.