CVE-2005-3642 in Informix Dynamic Database server
Summary
by MITRE
IBM Informix Dynamic Database server running on Windows XP with Simple File Sharing enabled, allows remote attackers to bypass authentication and log on to the guest account by supplying an invalid username.
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Analysis
by VulDB Data Team • 07/28/2017
The vulnerability identified as CVE-2005-3642 represents a significant authentication bypass flaw in IBM Informix Dynamic Database server when deployed on Windows XP systems with Simple File Sharing enabled. This weakness stems from the improper handling of authentication requests within the database server's interaction with the underlying Windows operating system. The vulnerability specifically affects environments where Windows XP's Simple File Sharing feature is active, creating an unintended pathway for unauthorized access that bypasses normal authentication mechanisms.
The technical flaw manifests when the Informix Dynamic Database server processes authentication requests from remote attackers. When an invalid username is provided during the authentication process, the system incorrectly grants access to the guest account rather than properly rejecting the attempt. This behavior occurs due to the server's failure to properly validate authentication credentials against the Windows XP file sharing configuration. The vulnerability exploits the interaction between the database server and the Windows authentication subsystem, where the server's authentication logic does not adequately distinguish between legitimate and invalid user attempts, particularly when Simple File Sharing is enabled.
The operational impact of this vulnerability is substantial as it allows remote attackers to gain unauthorized access to database systems without proper credentials. Attackers can leverage this weakness to establish connections to the database server and potentially access sensitive data stored within the Informix database. The guest account access provides limited but potentially harmful privileges, including the ability to read database information, potentially modify data, or perform administrative functions depending on the guest account's permissions. This vulnerability is particularly dangerous in enterprise environments where database security is critical and unauthorized access could lead to data breaches, information disclosure, or system compromise.
This vulnerability aligns with CWE-287, which addresses improper authentication issues in software systems, and represents a classic example of weak authentication controls that allow privilege escalation through improper credential validation. From an attack perspective, this flaw maps to the MITRE ATT&CK technique T1078 for valid accounts, specifically targeting the use of guest accounts as a means of maintaining access. Organizations should implement immediate mitigations including disabling Simple File Sharing on Windows XP systems running Informix Dynamic Database, updating to supported operating system versions, and implementing proper network segmentation to limit remote access to database servers. Additionally, administrators should review and restrict guest account permissions, implement strong access controls, and consider deploying network intrusion detection systems to monitor for suspicious authentication patterns that may indicate exploitation attempts.