CVE-2009-2355 in NullLogic Groupware
Summary
by MITRE
The forum module in NullLogic Groupware 1.2.7 allows remote authenticated users to cause a denial of service (application crash) by specifying (1) an empty string or (2) a non-numeric string when selecting a forum, related to the fmessagelist function.
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Analysis
by VulDB Data Team • 12/10/2017
The vulnerability identified as CVE-2009-2355 resides within the forum module of NullLogic Groupware version 1.2.7, representing a classic input validation flaw that can be exploited to trigger a denial of service condition. This issue affects authenticated users who can manipulate the application's behavior through specific input parameters during forum selection operations. The vulnerability specifically targets the fmessagelist function which processes user requests to display forum messages, creating a scenario where malformed input can cause the application to crash and become unavailable to legitimate users.
The technical nature of this vulnerability stems from inadequate input sanitization within the forum module's message listing functionality. When users with valid authentication credentials attempt to select a forum, the system fails to properly validate the input parameters before processing them through the fmessagelist function. This allows attackers to submit either empty strings or non-numeric strings as forum identifiers, which the application cannot handle gracefully. The lack of proper validation creates a path where the application's internal processing logic encounters unexpected data types that cause memory corruption or exception handling failures, ultimately leading to application termination.
From an operational perspective, this vulnerability presents a significant risk to system availability and service integrity within the NullLogic Groupware environment. The denial of service impact means that legitimate users who are authenticated to the system can be effectively prevented from accessing forum functionality, potentially disrupting collaborative workflows and communication channels that depend on this module. The attack vector requires only authenticated access, making it particularly dangerous as it can be exploited by insiders or compromised accounts. The vulnerability affects the availability aspect of the CIA triad and can be categorized under CWE-20, which represents "Improper Input Validation" in the Common Weakness Enumeration catalog.
The exploitation of this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1499 category for "Network Denial of Service" and T1566 for "Phishing with Social Engineering" as unauthorized access can be achieved through credential compromise. The attack requires minimal technical expertise since it leverages existing authenticated sessions to trigger application instability. Security professionals should note that this vulnerability demonstrates the importance of implementing robust input validation at all levels of application processing, particularly in modules that handle user-submitted data. The flaw highlights the critical need for defensive programming practices including proper error handling, data type checking, and validation routines before processing user inputs.
Mitigation strategies for CVE-2009-2355 should focus on implementing comprehensive input validation mechanisms within the forum module's fmessagelist function. System administrators should ensure that all input parameters are validated for proper data types and content before processing, with specific measures to reject empty strings and non-numeric values that do not conform to expected forum identifier formats. The recommended approach includes implementing strict type checking, input sanitization, and robust error handling procedures that prevent malformed data from causing application crashes. Additionally, regular security updates and patches should be applied to address this vulnerability in the NullLogic Groupware platform. Organizations should also consider implementing monitoring solutions to detect unusual patterns of forum access attempts that may indicate exploitation attempts, while maintaining proper access controls and authentication mechanisms to limit the attack surface.