CVE-2021-41286 in MultiCash Desktop
Summary
by MITRE • 10/05/2021
Omikron MultiCash Desktop 4.00.008.SP5 relies on a client-side authentication mechanism. When a user logs into the application, the validity of the password is checked locally. All communication to the database backend is made via the same technical account. Consequently, an attacker can attach a debugger to the process or create a patch that manipulates the behavior of the login function. When the function always returns the success value (corresponding to a correct password), an attacker can login with any desired account, such as the administrative account of the application.
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Analysis
by VulDB Data Team • 10/09/2021
The vulnerability described in CVE-2021-41286 represents a critical authentication bypass flaw in Omikron MultiCash Desktop version 4.00.008.SP5 that fundamentally undermines the application's security posture. This issue stems from a flawed client-side authentication implementation where password validation occurs locally on the user's machine rather than being properly verified against a secure backend system. The vulnerability creates a dangerous scenario where the application's security model relies entirely on client-side checks that can be easily circumvented through reverse engineering or code manipulation techniques.
The technical exploitation of this vulnerability occurs through several attack vectors that align with the attack pattern taxonomy. An attacker can employ dynamic analysis techniques to attach debuggers to the running process or utilize binary patching methods to modify the application's behavior. This approach corresponds to attack techniques categorized under software exploitation and code manipulation within the ATT&CK framework. The flaw specifically manifests when the login function is manipulated to always return a success value, effectively bypassing the password validation mechanism entirely. This type of vulnerability is classified as a client-side validation bypass and falls under CWE-604, which addresses the improper restriction of operations within a limited context, and CWE-305, which covers authentication bypass through multiple means.
The operational impact of this vulnerability is severe and far-reaching, as it allows an attacker to gain unauthorized administrative access to the application. Since all database communication is performed using the same technical account regardless of the user's actual credentials, successful exploitation enables complete compromise of the application's administrative functions. This creates a pathway for attackers to manipulate sensitive data, modify system configurations, and potentially establish persistent access to the underlying infrastructure. The vulnerability essentially removes any meaningful authentication barrier between unauthorized users and privileged application functions, making it particularly dangerous in enterprise environments where such applications may handle critical financial or operational data.
Mitigation strategies for this vulnerability must address both the immediate security gap and the underlying architectural flaw. Organizations should implement proper server-side authentication mechanisms that do not rely on client-side validation for critical access controls. The recommended approach involves deploying secure authentication protocols that verify credentials against a centralized authentication server rather than relying on local validation. Additionally, application hardening measures should be implemented including code obfuscation, integrity checking, and anti-debugging techniques to make reverse engineering more difficult. The implementation of proper input validation and secure coding practices should be enforced throughout the application lifecycle to prevent similar issues in future releases. Organizations should also consider network segmentation and monitoring solutions to detect unauthorized access attempts and potential exploitation activities. This vulnerability highlights the importance of following secure coding guidelines and implementing defense-in-depth strategies that do not rely solely on client-side security controls for critical authentication functions.