CVE-2001-0271 in Mailnews
Summary
by MITRE
mailnews.cgi 1.3 and earlier allows remote attackers to execute arbitrary commands via a user name that contains shell metacharacters.
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Analysis
by VulDB Data Team • 05/10/2019
The vulnerability identified as CVE-2001-0271 affects mailnews.cgi version 1.3 and earlier, representing a critical command injection flaw in web-based email notification systems. This vulnerability resides in the input validation mechanisms of the mailnews.cgi script which is commonly used for sending email notifications from web forms or applications. The flaw stems from insufficient sanitization of user-provided input, specifically the username parameter that is processed without proper escaping or filtering of shell metacharacters. When an attacker submits a malicious username containing characters such as semicolons, ampersands, or backticks, these metacharacters can be interpreted by the underlying shell executing the script, leading to unauthorized command execution on the server. This type of vulnerability falls under the CWE-77 category known as "Improper Neutralization of Special Elements used in a Command ('Command Injection')", which is classified as a high-severity issue in the CWE taxonomy. The attack vector leverages the principle of insufficient input validation and improper output encoding, where user data flows directly into system commands without proper sanitization.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the ability to perform arbitrary operations on the compromised system. An attacker could potentially escalate privileges, access sensitive files, modify system configurations, or even establish persistent backdoors through the executed commands. The vulnerability affects web applications that rely on mailnews.cgi for email delivery functionality, particularly those running on unix-based systems where shell command execution is possible. This flaw can be exploited through various means including web forms that submit email addresses, contact pages, or any interface that passes user input to the mailnews.cgi script for processing. The attack requires minimal sophistication as it only requires the insertion of shell metacharacters into the username field, making it particularly dangerous in environments where the script runs with elevated privileges or where the system has access to sensitive resources.
Mitigation strategies for CVE-2001-0271 should focus on input validation, output encoding, and proper command execution practices. The primary defense involves implementing strict input sanitization where all user-provided data is filtered to remove or escape shell metacharacters before processing. This approach aligns with the ATT&CK technique T1059.001 for Command and Scripting Interpreter, where the goal is to prevent the execution of unintended commands. Organizations should upgrade to patched versions of mailnews.cgi or replace the vulnerable script with a more secure implementation that properly validates and sanitizes all input parameters. Additionally, implementing proper privilege separation ensures that the mailnews.cgi script runs with minimal required permissions, limiting the potential impact of successful exploitation. Network-based mitigations such as web application firewalls can provide additional protection by detecting and blocking suspicious input patterns. The vulnerability demonstrates the importance of following secure coding practices as outlined in OWASP Top Ten, specifically addressing injection flaws that can lead to arbitrary code execution. Regular security audits and input validation testing should be implemented to identify similar vulnerabilities in other components of the application stack, as this type of flaw often indicates broader security weaknesses in the system architecture.