CVE-2005-0306 in MercuryBoard
Summary
by MITRE
MercuryBoard 1.1.1 allows remote attackers to gain sensitive information via an HTTP request with the n parameter set to 0, which causes a divide-by-zero error and reveals the path in the resulting error message.
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Analysis
by VulDB Data Team • 07/05/2018
The vulnerability described in CVE-2005-0306 affects MercuryBoard version 1.1.1, a web-based bulletin board system that was widely used in the early 2000s for community forums and discussion platforms. This security flaw represents a classic example of improper error handling that exposes sensitive system information to remote attackers. The vulnerability specifically manifests when an attacker crafts a malicious HTTP request with the parameter 'n' set to zero, triggering a mathematical division by zero condition within the application's processing logic.
The technical mechanism behind this vulnerability involves a divide-by-zero error occurring in the MercuryBoard application's code execution flow. When the 'n' parameter equals zero, the system attempts to perform a mathematical operation that results in division by zero, which in turn generates an error message containing the absolute path of the application on the server filesystem. This type of error handling flaw falls under CWE-391, which specifically addresses unhandled exceptions and improper error conditions that can reveal system information to unauthorized parties. The error message reveals critical path information that could be leveraged by attackers to understand the application's deployment structure and potentially identify other vulnerabilities or misconfigurations.
From an operational perspective, this vulnerability creates a significant risk for systems running MercuryBoard 1.1.1 as it provides attackers with direct access to filesystem paths that can be used for further exploitation. The disclosed path information can aid in crafting more sophisticated attacks such as local file inclusion vulnerabilities or directory traversal exploits. The attack vector is particularly concerning because it requires minimal effort from an attacker - simply sending a malformed HTTP request with parameter 'n' set to zero. This vulnerability directly aligns with ATT&CK technique T1212, which involves exploitation of software vulnerabilities to gain information about the target system. The exposure of system paths also supports techniques under T1083, which involves discovering system information through various means.
The impact of this vulnerability extends beyond simple information disclosure as it provides attackers with foundational knowledge about the target environment. The revealed paths can be used to understand the application's file structure, potentially identifying sensitive files or directories that might be accessible through other attack vectors. Security professionals should note that this vulnerability represents a fundamental flaw in the application's defensive programming practices, where proper error handling and input validation were not implemented to prevent such information leakage. The vulnerability demonstrates the importance of implementing robust error handling mechanisms that do not expose internal system details to external users, aligning with security best practices outlined in various industry standards including ISO 27001 and NIST cybersecurity frameworks.
Mitigation strategies for this vulnerability involve immediate patching of the MercuryBoard application to version 1.1.2 or later, which would contain the necessary code fixes to properly handle division by zero conditions without exposing system paths. Organizations should also implement proper input validation to ensure that parameters like 'n' are properly sanitized before processing, preventing the execution path that leads to the error condition. Additionally, web application firewalls and intrusion detection systems can be configured to monitor for and block requests containing suspicious parameter values that might trigger similar error conditions. The vulnerability underscores the critical need for comprehensive security testing including error handling scenarios, as well as regular security assessments to identify and remediate similar flaws in legacy applications that may continue to be in use despite their age and known vulnerabilities.