CVE-2005-0595 in BadBlue
Summary
by MITRE
Buffer overflow in ext.dll in BadBlue 2.55 allows remote attackers execute arbitrary code via a long mfcisapicommand parameter.
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability identified as CVE-2005-0595 represents a critical buffer overflow flaw within the ext.dll component of BadBlue web server version 2.55. This vulnerability exists within the handling of HTTP requests and specifically targets the mfcisapacommand parameter that is processed through the Microsoft Internet Information Services (IIS) ISAPI extension interface. The flaw stems from inadequate input validation and bounds checking within the web server's response handling mechanism, creating an exploitable condition where maliciously crafted requests can overwrite adjacent memory locations in the process heap. The vulnerability manifests when a remote attacker sends a specially crafted HTTP request containing an excessively long mfcisapacommand parameter that exceeds the allocated buffer space, leading to memory corruption that can be leveraged for arbitrary code execution.
This buffer overflow vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent heap memory. The attack vector operates through the web server's ISAPI extension interface, making it particularly dangerous as it can be exploited through standard HTTP traffic without requiring any special authentication or local access privileges. The vulnerability affects the core web server functionality and can be triggered through any HTTP request that includes the mfcisapacommand parameter, making it highly exploitable in environments where BadBlue servers are accessible from the internet. The flaw resides in the ext.dll module which is responsible for processing various web server extensions and ISAPI requests, indicating that the vulnerability impacts the fundamental request processing capabilities of the software.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable complete system compromise when exploited successfully. Attackers can leverage this condition to inject malicious code into the web server process memory, potentially gaining full administrative control over the affected system. The vulnerability allows for privilege escalation from the web server user context to system-level privileges, depending on how the web server is configured and what resources are accessible through the compromised service. Additionally, the memory corruption can lead to denial of service conditions where the web server crashes or becomes unresponsive, creating availability issues that can impact business operations. The attack can be automated and does not require specialized knowledge of the underlying system architecture, making it particularly dangerous for unpatched systems in production environments.
Mitigation strategies for CVE-2005-0595 should include immediate patching of the BadBlue web server software to version 2.56 or later, which contains the necessary fixes for the buffer overflow condition. Organizations should also implement network-level restrictions such as firewalls and access control lists to limit exposure of vulnerable web servers to untrusted networks. The implementation of input validation controls at the network perimeter can help detect and block malicious requests before they reach the vulnerable web server components. Security monitoring should be enhanced to detect unusual traffic patterns or attempts to exploit the mfcisapacommand parameter, with intrusion detection systems configured to alert on suspicious HTTP request structures. Additionally, system administrators should consider implementing application whitelisting policies to restrict execution of unauthorized code and employ memory protection mechanisms such as stack canaries or address space layout randomization to make exploitation more difficult. The vulnerability demonstrates the importance of regular security updates and proper input validation practices in web server software development, aligning with ATT&CK technique T1059 for command and script interpreter execution through web-based attack vectors.