CVE-2007-5253 in Cart32
Summary
by MITRE
c32web.exe in McMurtrey/Whitaker Cart32 before 6.4 allows remote attackers to read arbitrary files via the ImageName parameter in a GetImage action, by appending a NULL byte (%00) sequence followed by an image file extension, as demonstrated by a request for a ".txt%00.gif" file. NOTE: this might be a directory traversal vulnerability.
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Analysis
by VulDB Data Team • 10/19/2024
The vulnerability identified as CVE-2007-5253 affects the c32web.exe component within McMurtrey/Whitaker Cart32 versions prior to 6.4, representing a critical security flaw that enables remote attackers to perform unauthorized file access operations. This vulnerability specifically targets the GetImage action functionality and exploits a flaw in how the application processes the ImageName parameter, creating an avenue for arbitrary file reading through crafted malicious requests. The vulnerability manifests when attackers append a NULL byte sequence followed by an image file extension to manipulate the application's file handling behavior, as demonstrated by the specific example of requesting ".txt%00.gif" files.
The technical implementation of this vulnerability stems from inadequate input validation and improper sanitization of user-supplied parameters within the Cart32 web application. When the application receives a request containing the ImageName parameter with the NULL byte termination, it fails to properly validate or sanitize the input before processing, allowing the application to interpret the request as if it were accessing a legitimate image file while actually traversing the file system to retrieve sensitive files. This behavior aligns with directory traversal vulnerabilities as classified under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly referred to as path traversal or directory traversal attacks. The vulnerability exploits a fundamental flaw in input handling where the application does not adequately check for or strip special characters that could alter the intended file access path.
From an operational impact perspective, this vulnerability presents significant risks to web application security and data confidentiality. Attackers can leverage this flaw to access sensitive files that should remain protected within the application's file system, potentially including configuration files, database connection details, user credentials, or other sensitive information stored on the server. The ability to read arbitrary files through a remote attack vector means that an attacker does not require local system access or physical presence to exploit this vulnerability, making it particularly dangerous for web applications that host sensitive data. This vulnerability could lead to complete system compromise if attackers can access critical system files or configuration data that might reveal additional attack vectors or system weaknesses. The impact extends beyond simple information disclosure, as it can facilitate further exploitation attempts including privilege escalation or lateral movement within the network infrastructure.
The exploitation of this vulnerability demonstrates how seemingly minor input validation flaws can create major security risks in web applications, particularly those that handle file operations and user-supplied data. Organizations using affected versions of Cart32 should immediately implement mitigations including upgrading to version 6.4 or later, which contains the necessary patches to address this vulnerability. Additional defensive measures include implementing proper input validation and sanitization for all user-supplied parameters, particularly those used in file operations, and configuring web application firewalls to detect and block suspicious patterns including NULL byte sequences in file requests. This vulnerability also highlights the importance of following security best practices such as the principle of least privilege, where applications should only have access to the files and resources necessary for their operation, and proper error handling that does not expose internal system information to unauthorized users. The ATT&CK framework categorizes this type of vulnerability under privilege escalation and credential access techniques, emphasizing the potential for attackers to use such flaws as initial access points for more extensive compromise operations.