CVE-2005-2403 in RealChat
Summary
by MITRE
The login protocol in RealChat 3.5.1b does not use authentication, which allows remote attackers to log on as other users by sniffing the beginning of a chat session and replaying it via a modified username.
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Analysis
by VulDB Data Team • 07/10/2018
The vulnerability described in CVE-2005-2403 represents a critical flaw in the RealChat 3.5.1b instant messaging application that fundamentally undermines the security of user authentication mechanisms. This weakness resides in the login protocol implementation where proper authentication procedures are completely absent, creating a pathway for malicious actors to gain unauthorized access to user accounts. The vulnerability specifically affects the initial chat session establishment phase where authentication credentials are not properly validated or secured.
The technical exploitation of this vulnerability occurs through network packet sniffing techniques that allow attackers to capture the initial communication packets between client and server during the login process. These captured packets contain the username information and potentially other identifying details that form the basis of the authentication handshake. Once obtained, attackers can modify the captured username field and replay the entire packet sequence to the server, effectively impersonating legitimate users without requiring any valid credentials. This type of attack falls under the category of credential replay attacks and session hijacking techniques.
The operational impact of this vulnerability extends beyond simple unauthorized access as it enables attackers to potentially intercept and manipulate communications between users. Since the vulnerability allows for arbitrary username modification during the login process, attackers can not only access accounts but also impersonate specific users within the chat environment. This creates opportunities for man-in-the-middle attacks, where malicious actors can position themselves between communicating parties and control the conversation flow. The vulnerability directly violates security principles of authentication and authorization, creating a persistent threat vector that remains active as long as the vulnerable application is in use.
This vulnerability aligns with CWE-305 authentication weaknesses and represents a classic example of insufficient authentication mechanisms as outlined in the CWE database. The flaw also maps to several ATT&CK techniques including T1566 for credential access through network sniffing and T1075 for legitimate credentials usage. The lack of proper authentication in the login protocol creates a fundamental security gap that allows attackers to bypass the normal access control mechanisms entirely. Organizations using RealChat 3.5.1b would be particularly vulnerable to insider threats and external attacks, as the vulnerability does not require complex exploitation techniques or elevated privileges to leverage. The attack vector is relatively simple and can be executed by anyone with network access and basic packet analysis capabilities.
Mitigation strategies for this vulnerability require immediate patching of the RealChat application to implement proper authentication mechanisms including secure session management and credential validation. Network administrators should implement network segmentation and monitoring to detect unusual login patterns and packet replay activities. The most effective solution involves upgrading to a patched version of RealChat that implements secure authentication protocols and proper session handling. Additionally, organizations should consider implementing network access controls and intrusion detection systems to monitor for potential exploitation attempts. The vulnerability highlights the critical importance of proper authentication implementation in networked applications and serves as a reminder of the potential consequences of inadequate security controls in communication software.