CVE-2008-1135 in INterneSErvicesLosungen
Summary
by MITRE
OMEGA (aka Omegasoft) INterneSErvicesLosungen (INSEL) 7 generates different responses depending on whether or not a username is valid in a failed login attempt, which allows remote attackers to enumerate valid usernames.
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Analysis
by VulDB Data Team • 09/19/2018
The vulnerability identified as CVE-2008-1135 affects OMEGA INterneSErvicesLosungen (INSEL) version 7, a web application framework that exhibits inconsistent error handling behavior during authentication processes. This flaw represents a classic account enumeration vulnerability that violates fundamental security principles of authentication systems. The vulnerability stems from the application's design where it provides different response messages or behaviors when authentication fails based on whether the attempted username exists in the system. This differential response mechanism creates a clear information disclosure channel that adversaries can exploit to determine valid user accounts within the system.
The technical implementation of this vulnerability occurs at the authentication layer where the application fails to maintain consistent error responses regardless of the authentication outcome. When an attacker submits a login request with a non-existent username, the system typically returns a different error message compared to when a valid username is provided but an incorrect password is submitted. This inconsistency allows for systematic username enumeration through automated testing procedures where attackers can submit numerous username combinations and observe the varying responses to identify which usernames are valid. The vulnerability directly maps to CWE-200, which describes improper exposure of sensitive information, and specifically relates to CWE-305, which addresses authentication mechanisms that are vulnerable to attack through the use of information about the authentication process.
The operational impact of this vulnerability extends beyond simple account enumeration, as it provides attackers with critical intelligence for subsequent attack phases. Once valid usernames are identified, attackers can proceed with password spraying, brute force attacks, or targeted credential stuffing campaigns against the discovered accounts. This vulnerability particularly affects systems where user account names are predictable or follow common naming conventions, making the enumeration process more efficient. The attack surface is further expanded when considering that many organizations maintain user directories or databases that are accessible through the same authentication mechanisms, potentially allowing for broader reconnaissance activities. According to ATT&CK framework, this vulnerability aligns with T1078, which covers valid accounts as a means of gaining access, and T1566, which covers credential access through social engineering or information gathering techniques.
Mitigation strategies for CVE-2008-1135 should focus on implementing consistent error handling throughout the authentication process. Organizations must ensure that all authentication failures return identical error messages regardless of whether the username exists or not, eliminating any information leakage that could aid enumeration attempts. The system should also implement account lockout mechanisms, rate limiting, and monitoring for suspicious authentication patterns. Additionally, organizations should consider implementing multi-factor authentication to add additional layers of security beyond simple username-password combinations. The solution approach should follow security best practices outlined in NIST SP 800-63B, which emphasizes the importance of consistent error handling and proper authentication design. Regular security assessments and penetration testing should include checks for similar enumeration vulnerabilities across all authentication systems to prevent similar issues from persisting in the environment.