CVE-2007-5771 in Flatnuke3
Summary
by MITRE
Flatnuke 3 (aka FlatnuX) allows remote attackers to obtain administrative access via a myforum%00 cookie.
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Analysis
by VulDB Data Team • 10/09/2024
The vulnerability identified as CVE-2007-5771 affects Flatnuke 3, also known as FlatnuX, a content management system that was prevalent in the late 2000s. This issue represents a critical security flaw that enables remote attackers to escalate privileges and gain administrative control over affected systems. The vulnerability stems from improper input validation and handling of cookie data within the application's authentication mechanisms. Attackers can exploit this weakness by crafting a malicious cookie value containing the string myforum followed by a null byte sequence %00, which allows them to bypass normal authentication procedures and assume administrative privileges. The flaw demonstrates a classic case of buffer over-read or null byte truncation vulnerability, where the application fails to properly sanitize cookie values before processing them. This type of vulnerability is particularly dangerous because it can be exploited remotely without requiring any prior authentication or access to the system.
The technical implementation of this vulnerability involves the application's cookie handling mechanism failing to properly validate or sanitize the myforum cookie value before using it in authentication checks. When a null byte %00 is included in the cookie value, it can cause the application's string processing functions to truncate the cookie data at that point, potentially allowing an attacker to manipulate the authentication flow. This behavior aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow conditions, though the specific implementation here involves null byte manipulation rather than traditional buffer overflows. The vulnerability operates at the application layer and specifically targets the authentication and session management components of Flatnuke 3, making it particularly impactful for any system running this CMS version.
The operational impact of CVE-2007-5771 is severe and far-reaching for organizations using Flatnuke 3 systems. Successful exploitation allows attackers to gain complete administrative control over the affected web applications, enabling them to modify content, add or remove users, access sensitive data, and potentially use the compromised system as a launch point for further attacks within the network. The remote nature of the exploit means that attackers can leverage this vulnerability from anywhere on the internet without requiring physical access or local network presence. This vulnerability directly maps to several tactics in the MITRE ATT&CK framework, specifically covering privilege escalation techniques under the T1068 category and credential access through T1550. Organizations running affected systems face significant risk of data breaches, service disruption, and potential compromise of entire network infrastructures.
Mitigation strategies for this vulnerability should focus on immediate patching and code-level fixes. The primary solution involves implementing proper input validation and sanitization for all cookie values, ensuring that null bytes and other potentially malicious characters are properly handled or rejected. System administrators should update to the latest version of Flatnuke or implement custom patches that address the specific cookie handling flaw. Network-level protections such as web application firewalls can provide additional defense-in-depth measures, though they should not be considered a substitute for proper code-level fixes. Organizations should also implement comprehensive monitoring and logging of authentication attempts to detect potential exploitation attempts. The vulnerability highlights the importance of secure coding practices and proper input validation, particularly in authentication mechanisms. Security teams should conduct thorough audits of all cookie handling and session management code to identify similar vulnerabilities that may exist in other applications or systems within their environment. Regular security assessments and penetration testing can help identify and remediate such weaknesses before they can be exploited by malicious actors.