CVE-2002-0532 in EMU
Summary
by MITRE
EMU Webmail allows local users to execute arbitrary programs via a .. (dot dot) in the HTTP Host header that points to a Trojan horse configuration file that contains a pageroot specifier that contains shell metacharacters.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/20/2019
The vulnerability described in CVE-2002-0532 represents a classic path traversal attack targeting the EMU Webmail application. This flaw exists in the HTTP Host header processing mechanism where the application fails to properly sanitize input containing directory traversal sequences. The vulnerability specifically exploits the use of double dots .. within the Host header to manipulate file access patterns, allowing attackers to bypass normal access controls and potentially execute arbitrary code.
The technical implementation of this vulnerability stems from improper input validation and sanitization within the webmail application's configuration handling process. When the Host header contains a .. sequence pointing to a Trojan horse configuration file, the application interprets this as a legitimate path specification rather than malicious input. The presence of a pageroot specifier within the configuration file combined with shell metacharacters creates an execution environment where commands can be injected and executed with the privileges of the web server process. This represents a critical security flaw that maps to CWE-22 Path Traversal and CWE-78 Command Injection, both of which are fundamental weaknesses in web application security.
From an operational perspective, this vulnerability presents a severe risk to organizations relying on EMU Webmail as it allows local attackers to execute arbitrary programs on the affected system. The attack vector is particularly dangerous because it requires only local access to the system, meaning that an attacker with minimal privileges can escalate their access level to execute commands as the web server user. This could potentially lead to complete system compromise, data exfiltration, or further lateral movement within the network. The vulnerability also aligns with ATT&CK technique T1059 Command and Scripting Interpreter, where adversaries leverage legitimate system tools to execute malicious code, and T1068 Exploitation for Privilege Escalation to gain elevated system access.
Mitigation strategies for this vulnerability should focus on implementing strict input validation and sanitization for all HTTP headers, particularly the Host header. Organizations should ensure that the webmail application properly escapes or rejects directory traversal sequences and shell metacharacters in configuration files. The recommended approach includes implementing proper path normalization, restricting file access to predefined directories, and ensuring that configuration files are properly validated before being processed. Additionally, network segmentation and access controls should be implemented to limit local access to the web server. System administrators should also consider implementing web application firewalls and monitoring for suspicious Host header patterns to detect potential exploitation attempts. The vulnerability highlights the importance of following secure coding practices and input validation as outlined in OWASP Top Ten and NIST Cybersecurity Framework guidelines for preventing such critical security flaws.