CVE-2000-0411 in FormMail
Summary
by MITRE
Matt Wright's FormMail CGI script allows remote attackers to obtain environmental variables via the env_report parameter.
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Analysis
by VulDB Data Team • 04/21/2026
The vulnerability identified as CVE-2000-0411 affects the Matt Wright FormMail CGI script, a widely used web application for processing form submissions on websites. This particular flaw resides in how the script handles the env_report parameter, which is designed to provide environmental variable information to administrators for debugging purposes. The issue stems from insufficient input validation and sanitization within the script's parameter processing logic, creating a path for remote attackers to manipulate the env_report functionality and extract sensitive system information.
The technical implementation of this vulnerability allows an attacker to inject malicious input through the env_report parameter, which then gets processed and potentially exposed to unauthorized parties. When the FormMail script processes this parameter, it fails to properly validate or sanitize the input before incorporating it into system-level operations. This weakness enables attackers to access environmental variables that typically contain sensitive information about the server environment, including file paths, system configurations, and potentially authentication details. The vulnerability represents a classic case of improper input handling that can lead to information disclosure, making it particularly dangerous for attackers seeking to gather intelligence for further exploitation.
From an operational impact perspective, this vulnerability significantly increases the attack surface for compromised web servers running the affected FormMail script. The exposure of environmental variables can provide attackers with critical information about the underlying system architecture, including directory structures, available system tools, and potentially sensitive configuration details. Security professionals should note that this vulnerability aligns with CWE-20, which describes improper input validation, and represents a form of information disclosure that can facilitate subsequent attacks. The impact extends beyond simple information gathering as this data can be used to craft more sophisticated attacks against the target system or network infrastructure.
The exploitation of this vulnerability typically requires minimal technical expertise and can be accomplished through simple web-based requests that manipulate the env_report parameter. This accessibility makes it particularly concerning as it can be leveraged by attackers with basic web security knowledge. Organizations should consider implementing mitigations such as input validation, parameter sanitization, and access controls around CGI scripts. The vulnerability also highlights the importance of proper security auditing of legacy web applications and demonstrates how seemingly benign features like environmental reporting can become security risks when not properly implemented. According to ATT&CK framework, this vulnerability maps to T1083 (File and Directory Discovery) and T1592 (Gather Victim Host Information) as attackers can use the exposed environmental data to better understand the target system. Additionally, this issue underscores the need for regular security assessments and the importance of keeping web applications updated to address known vulnerabilities that could otherwise remain unpatched for extended periods.