CVE-2001-0393 in Financials Server
Summary
by MITRE
Navision Financials Server 2.0 allows remote attackers to cause a denial of service via a series of connections to the server without providing a username/password combination, which consumes the license limits.
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Analysis
by VulDB Data Team • 04/08/2019
The vulnerability identified as CVE-2001-0393 affects Navision Financials Server version 2.0, representing a classic denial of service attack vector that exploits the server's license management mechanism. This weakness demonstrates a fundamental flaw in the authentication and resource allocation process where the system fails to properly handle unauthorized connection attempts. The vulnerability operates by exploiting the server's license counting mechanism, which tracks active connections and user sessions to enforce licensing restrictions. When attackers establish multiple connections without providing valid credentials, the system consumes license slots without proper authentication, leading to legitimate users being unable to access the service. This represents a significant security flaw in the server's access control implementation and resource management protocols.
The technical implementation of this vulnerability stems from the server's inadequate validation of connection requests and failure to distinguish between legitimate and malicious connection attempts. The system maintains a finite license pool that is consumed by each connection attempt, regardless of whether authentication is provided or successful. This design flaw allows an attacker to exhaust the available licenses through repeated unauthorized connection attempts, effectively preventing legitimate users from accessing the financial server. The vulnerability specifically targets the server's license management subsystem, where connection counts are incremented without proper authentication verification, creating a resource exhaustion scenario that results in service disruption. According to CWE classification, this vulnerability maps to CWE-400, which addresses resource exhaustion conditions in software systems, and CWE-305, which covers authentication bypass mechanisms that can lead to unauthorized access patterns.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the availability of critical financial data processing capabilities within organizations using Navision Financials Server. When legitimate users are unable to establish connections due to license exhaustion, business operations that depend on financial data access become severely impacted. This vulnerability particularly affects organizations that rely on strict licensing models for their financial systems, as it can be exploited to create extended periods of service unavailability. The attack requires minimal technical expertise to execute, making it a significant concern for organizations with limited security controls. From an ATT&CK framework perspective, this vulnerability aligns with T1499.004, which covers network denial of service attacks, and T1566.001, which addresses social engineering techniques that can be used to gain initial access for such attacks. The vulnerability also represents a failure in the principle of least privilege, as unauthorized connections can consume resources that should be reserved for authenticated users.
Organizations should implement immediate mitigations including connection rate limiting, authentication timeout mechanisms, and enhanced monitoring of license consumption patterns to detect abnormal connection behavior. The system should be configured to automatically terminate unauthorized connection attempts after a specified number of failed authentication attempts. Network-level controls such as firewalls and access control lists can help limit the attack surface by restricting access to the server from unauthorized networks. Additionally, implementing proper license management practices, including regular monitoring of active connections and user sessions, can help identify when the system is under attack. Organizations should also consider upgrading to newer versions of Navision Financials Server that address these licensing and authentication vulnerabilities. The implementation of intrusion detection systems that can identify patterns of license exhaustion attacks provides an additional layer of protection. From a compliance standpoint, this vulnerability impacts organizations that must maintain availability of financial systems and may affect adherence to regulatory requirements for business continuity and data access availability.