CVE-2005-1556 in Gamespy SDK CD-Key Validation Toolkit
Summary
by MITRE
Gamespy cd-key validation system allows remote attackers to cause a denial of service (cd-key already in use) by capturing and replaying a cd-key authorization session.
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Analysis
by VulDB Data Team • 07/23/2017
The vulnerability described in CVE-2005-1556 represents a significant weakness in the Gamespy cd-key validation system that enables remote attackers to execute denial of service attacks through session replay techniques. This flaw specifically targets the authorization process used by online gaming platforms to validate cd-keys and ensure legitimate usage. The vulnerability stems from insufficient session management and authentication mechanisms within the cd-key validation protocol, creating an exploitable condition where malicious actors can capture valid authorization sessions and replay them to exhaust available cd-key usage slots.
The technical implementation of this vulnerability exploits the lack of proper session token validation and timestamp checking within the cd-key authorization system. When a legitimate user authenticates a cd-key, the system generates an authorization session that should be unique and time-bound. However, the Gamespy validation system fails to implement adequate session uniqueness checks or temporal controls, allowing attackers to capture the session data through network sniffing or packet capture techniques. Once captured, these sessions can be replayed to the validation server, causing the system to incorrectly interpret the replayed authorization as a new legitimate request, thereby marking the cd-key as already in use and preventing legitimate users from accessing the game.
The operational impact of this vulnerability extends beyond simple service disruption to create broader security implications for online gaming platforms and their user bases. Attackers can systematically exhaust cd-key availability for specific titles, effectively locking out legitimate users from accessing games they have purchased. This creates a cascading effect where users cannot enjoy their legitimate purchases, leading to customer dissatisfaction and potential financial losses for game publishers. The vulnerability also demonstrates poor adherence to security best practices regarding session management and authentication protocols, as outlined in the CWE catalog under weakness categories related to authentication and session management failures.
From a threat modeling perspective, this vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the credential access and denial of service tactics. The attack vector specifically relates to network sniffing and replay attacks that bypass traditional authentication mechanisms. Security professionals should note that this vulnerability exemplifies the importance of implementing proper session handling, including unique session identifiers, time-based expiration, and replay detection mechanisms. The flaw also highlights the necessity of following secure coding practices as recommended by industry standards such as the OWASP Top Ten, which emphasizes the critical need for proper authentication and session management in web applications and network services.
Mitigation strategies for this vulnerability require immediate implementation of session token validation mechanisms, including the addition of cryptographic session identifiers, timestamp validation, and replay detection systems. System administrators should implement network monitoring to detect unusual authorization patterns and establish rate limiting controls to prevent abuse of the cd-key validation system. The fix should involve modifying the authorization protocol to ensure that each cd-key can only be validated once within a specified time window and that session replay attempts are properly detected and rejected. Additionally, publishers should consider implementing more robust authentication systems that utilize challenge-response mechanisms or other cryptographic approaches to prevent the capture and replay of authorization sessions, thereby protecting both their services and their customers from this class of denial of service attack.