CVE-2007-1832 in WebAPP
Summary
by MITRE
web-app.org WebAPP before 0.9.9.6 allows remote authenticated users to upload certain files (1) via a crafted filename or (2) by "using percent encoding in forms."
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Analysis
by VulDB Data Team • 08/28/2018
The vulnerability identified as CVE-2007-1832 affects web-app.org WebAPP versions prior to 0.9.9.6 and represents a critical file upload security flaw that enables authenticated remote attackers to execute arbitrary code on the affected system. This vulnerability stems from inadequate input validation and sanitization mechanisms within the file upload functionality, creating a pathway for malicious actors to bypass security controls and potentially gain unauthorized access to the underlying server infrastructure.
The technical implementation of this vulnerability manifests through two distinct attack vectors that exploit weaknesses in the application's file handling mechanisms. The first vector involves crafting malicious filenames that can bypass the application's validation checks, while the second vector utilizes percent encoding within forms to manipulate the upload process. Both approaches leverage the application's insufficient filtering of user-supplied input, allowing attackers to upload files with potentially harmful extensions or content that can be executed by the web server. This weakness directly maps to CWE-434, which describes the improper restriction of file uploads, and represents a classic example of insecure file handling that has been consistently documented across numerous web applications.
The operational impact of this vulnerability extends beyond simple privilege escalation, as successful exploitation can lead to complete system compromise and unauthorized access to sensitive data. An authenticated attacker who can upload malicious files can potentially execute arbitrary code on the server, install backdoors, or escalate privileges to gain administrative control over the web application and underlying infrastructure. The vulnerability is particularly dangerous because it requires only authenticated access, meaning that attackers who can obtain valid user credentials can exploit this flaw without requiring additional reconnaissance or exploitation techniques. This makes the vulnerability particularly attractive to threat actors who may have gained access through other means such as credential theft or social engineering attacks.
Mitigation strategies for CVE-2007-1832 should focus on implementing comprehensive file upload validation controls and following secure coding practices that address the root causes of the vulnerability. Organizations should implement strict file type validation by maintaining allowlists of approved file extensions and MIME types, rather than relying on denylists which are inherently insecure. The application must properly sanitize all user-supplied filenames, removing or encoding special characters including percent encoding sequences that could be used to manipulate the upload process. Additionally, uploaded files should be stored in a separate directory from the web root with appropriate permissions to prevent direct execution, and file content should be validated to ensure it matches the claimed file type. These controls align with the ATT&CK framework's defense-in-depth approach and directly address the techniques used in file upload exploitation. Organizations should also implement proper logging and monitoring to detect suspicious upload activities and ensure that all web applications are regularly updated to address known vulnerabilities, as this vulnerability was patched in version 0.9.9.6 of the affected software.