CVE-2000-0911 in IMP
Summary
by MITRE
IMP 2.2 and earlier allows attackers to read and delete arbitrary files by modifying the attachment_name hidden form variable, which causes IMP to send the file to the attacker as an attachment.
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Analysis
by VulDB Data Team • 10/12/2025
The vulnerability identified as CVE-2000-0911 represents a critical file system access flaw within the Internet Messaging Program IMP version 2.2 and earlier. This security weakness stems from inadequate input validation and improper handling of user-supplied data within the web-based email client interface. The vulnerability specifically targets the attachment_name hidden form variable that is used to manage file attachments during email composition and transmission processes. When an attacker manipulates this variable, the system fails to properly validate or sanitize the input, leading to unauthorized file system access. The flaw allows malicious actors to specify arbitrary file paths that the system will then process as if they were legitimate attachment names, creating a path traversal condition that can be exploited to access sensitive files on the server.
The technical implementation of this vulnerability leverages the inherent trust placed in form variables within web applications. The IMP application, designed to handle email attachments through a web interface, fails to implement proper access controls or path validation when processing the attachment_name parameter. This oversight creates a direct pathway for attackers to bypass normal file system permissions and access files that should remain protected. The vulnerability operates at the application layer and can be exploited through simple HTTP form submissions, making it particularly dangerous as it requires minimal technical expertise to execute successfully. The flaw essentially transforms the legitimate file attachment functionality into a vehicle for unauthorized file access, demonstrating poor input sanitization practices that are commonly associated with CWE-22 Path Traversal and CWE-77 Improper Neutralization of Special Elements used in a Command.
The operational impact of CVE-2000-0911 extends beyond simple unauthorized file access to encompass potential data breaches, system compromise, and information disclosure. Attackers can leverage this vulnerability to read sensitive configuration files, database credentials, application source code, and other confidential data stored on the server. The ability to delete arbitrary files further amplifies the threat, as it provides attackers with destructive capabilities that can be used for data corruption or system disruption. This vulnerability directly aligns with ATT&CK technique T1078 Valid Accounts, as it can be exploited by attackers who have already gained access to legitimate user accounts, and T1566 Phishing with Social Engineering, since the attack can be initiated through web-based interfaces that users interact with regularly. Organizations running affected versions of IMP face significant risk of unauthorized access to their email infrastructure, potentially compromising the confidentiality and integrity of email communications.
Mitigation strategies for CVE-2000-0911 require immediate implementation of input validation and access control measures within the IMP application. The most effective approach involves patching the application to version 2.3 or later, which contains the necessary security fixes. Organizations should also implement proper parameter validation for all form variables, particularly those that handle file paths or names. Input sanitization techniques should be employed to ensure that attachment_name values do not contain directory traversal sequences or other malicious path components. Additionally, implementing principle of least privilege access controls for the web application and its underlying file system can significantly reduce the impact of successful exploitation attempts. Network-level protections such as web application firewalls and intrusion detection systems can provide additional layers of defense, though these should not be considered substitutes for proper application-level fixes. The vulnerability serves as a critical reminder of the importance of secure coding practices and the necessity of thorough input validation in web applications, particularly those handling user-supplied data in file system operations.