CVE-2005-0635 in Email Server
Summary
by MITRE
Buffer overflow in Foxmail Server 2.0 allows remote attackers to execute arbitrary code via a long USER command.
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Analysis
by VulDB Data Team • 07/22/2017
The vulnerability identified as CVE-2005-0635 represents a critical buffer overflow flaw within Foxmail Server version 2.0 that enables remote code execution through malformed USER command inputs. This vulnerability resides in the email server software's handling of user authentication commands, specifically targeting the USER command that is part of the standard smtp protocol implementation. The flaw manifests when the server processes excessively long USER command parameters without proper input validation or boundary checking, creating a condition where memory allocated for command processing can be overwritten by malicious data. The buffer overflow occurs in the server's smtp service component that manages user authentication requests, making it a direct target for exploitation by remote attackers who can craft specially designed USER commands to trigger the vulnerable code path.
The technical implementation of this vulnerability follows established patterns of stack-based buffer overflow exploits where the attacker sends a USER command containing more data than the allocated buffer can accommodate. When the server processes this command, the excess data overflows into adjacent memory locations, potentially corrupting the stack frame and allowing an attacker to overwrite return addresses or function pointers. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, which is classified as a fundamental weakness in software design that directly enables arbitrary code execution. The attack vector is particularly dangerous because it operates over network protocols, requiring no local access or authentication to exploit, and can be executed from any remote location with network connectivity to the vulnerable server.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and potential data breach scenarios. An attacker who successfully exploits this vulnerability can gain full control over the Foxmail Server, potentially accessing stored email messages, user credentials, and sensitive communication data. The server environment becomes vulnerable to privilege escalation attacks, where the malicious code execution can occur with the privileges of the running service account. This vulnerability also creates opportunities for persistent backdoor installation and lateral movement within network environments where the server operates. From an ATT&CK framework perspective, this vulnerability maps directly to techniques involving remote code execution and privilege escalation, specifically targeting the server-side service components and leveraging protocol-based attack patterns.
Mitigation strategies for CVE-2005-0635 should prioritize immediate patching of the Foxmail Server software to address the buffer overflow condition through proper input validation and boundary checking. Organizations should implement network segmentation and firewall rules to restrict access to smtp ports, limiting exposure to unauthorized remote connections. Regular security assessments and input validation testing should be conducted to identify similar vulnerabilities in other server applications. The implementation of intrusion detection systems can help monitor for suspicious USER command patterns that might indicate exploitation attempts. Additionally, administrators should consider implementing application-level firewalls or proxy services that can filter and validate smtp protocol commands before they reach the vulnerable server components. The vulnerability also underscores the importance of regular software updates and vulnerability management programs to prevent exploitation of known security flaws in legacy systems.