CVE-2005-2226 in Outlook Express
Summary
by MITRE
Microsoft Outlook Express 6.0 leaks the default news server account when a user responds to a "watched" conversation thread, which could allow remote attackers to obtain sensitive information.
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Analysis
by VulDB Data Team • 06/07/2019
Microsoft Outlook Express 6.0 contains a critical information disclosure vulnerability that arises from improper handling of news server account credentials during conversation thread responses. This flaw exists within the application's implementation of the news server connection management system, where default account information is inadvertently exposed when users interact with watched conversation threads. The vulnerability specifically affects the way Outlook Express processes and displays account details when responding to newsgroup messages, creating an information leak that compromises user authentication credentials. The technical root cause stems from insufficient input validation and output sanitization within the application's news server protocol handling components, allowing the default account configuration to be transmitted in cleartext to remote servers. This issue represents a classic example of improper information exposure as classified under CWE-200, where sensitive data is unintentionally revealed to unauthorized parties. The operational impact of this vulnerability extends beyond simple credential leakage, as it enables remote attackers to gain unauthorized access to news server accounts and potentially leverage these credentials for further malicious activities. Attackers can exploit this weakness by simply responding to a watched conversation thread, making the attack vector particularly insidious as it requires minimal user interaction beyond normal email usage patterns. The vulnerability aligns with ATT&CK technique T1552.001 for unsecured credentials and T1071.004 for application layer protocols, as it involves the exposure of authentication data through news server communications. This flaw particularly affects users who maintain multiple news server accounts or those who rely on default configurations, as the leaked information includes not only usernames but potentially password information stored in the application's configuration files. The security implications are significant given that Outlook Express 6.0 was widely deployed in enterprise environments, making this vulnerability a prime target for attackers seeking to establish persistent access to corporate communication systems. Organizations using this version of Outlook Express should immediately implement mitigation strategies including disabling newsgroup functionality, implementing network monitoring to detect unusual account access patterns, and deploying application whitelisting policies to prevent unauthorized access to vulnerable components. The vulnerability also highlights the importance of proper credential management and secure configuration practices within legacy applications, as the flaw demonstrates how default configurations can create security risks when not properly secured. This issue underscores the critical need for comprehensive security testing of email clients and news server integration components, particularly in environments where legacy software continues to be deployed without adequate security updates or patches. The exposure of default news server account information creates a pathway for attackers to conduct credential stuffing attacks against other services where users may have reused passwords, amplifying the overall security impact of this single vulnerability.