CVE-2002-2351 in Eudora
Summary
by MITRE
Eudora 5.1 allows remote attackers to bypass security warnings and possibly execute arbitrary code via attachments with names containing a trailing "." (dot).
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Analysis
by VulDB Data Team • 07/05/2025
The vulnerability described in CVE-2002-2351 affects Eudora 5.1 email client software and represents a significant security flaw in how the application handles file attachments. This issue stems from improper validation of file names during attachment processing, creating a pathway for malicious actors to circumvent the application's built-in security mechanisms. The vulnerability specifically exploits the handling of filenames that contain trailing dots, which are commonly used in operating systems to indicate directory entries or special file types. When Eudora processes an attachment with such a filename, it fails to properly validate the file type and execution context, potentially allowing attackers to execute malicious code without user awareness.
The technical flaw manifests in the application's file extension recognition and validation logic. In Eudora 5.1, when a file attachment contains a trailing dot in its name, the software does not correctly interpret the file type or apply appropriate security checks. This behavior violates fundamental security principles and creates an attack vector where malicious actors can craft specially named attachments that bypass the application's warning systems. The vulnerability is particularly dangerous because it operates at the file system level, where the application's security model assumes proper file type identification and handling. This flaw aligns with CWE-174, which describes weaknesses in software that fail to properly handle file names or paths, and represents a classic case of inadequate input validation that can lead to privilege escalation or code execution.
The operational impact of this vulnerability extends beyond simple security bypasses to encompass potential system compromise and data exposure. Remote attackers can exploit this weakness to deliver malicious payloads that execute arbitrary code on vulnerable systems, potentially leading to full system compromise or data theft. The trailing dot manipulation technique allows attackers to circumvent security warnings that would normally alert users to potentially dangerous attachments, making the attack more stealthy and effective. This vulnerability directly relates to ATT&CK technique T1059, which involves executing malicious code through various attack vectors, and T1203, which focuses on exploiting software vulnerabilities to gain unauthorized access. The security implications are particularly severe in enterprise environments where email clients serve as primary attack vectors for phishing campaigns and malware distribution.
Mitigation strategies for this vulnerability should focus on immediate software updates and enhanced security configurations. Users should upgrade to Eudora versions that properly handle file name validation and implement stricter attachment processing policies. Organizations should deploy email filtering solutions that can identify and block suspicious file name patterns, particularly those containing trailing dots or other potentially malicious naming conventions. Network administrators should consider implementing additional security measures such as sandboxing email attachments before user access, deploying application whitelisting policies, and ensuring that email clients are properly configured to disable automatic execution of potentially dangerous file types. The vulnerability also highlights the importance of proper input validation and the need for comprehensive security testing of file handling mechanisms in email client software, emphasizing the principles outlined in the OWASP Top Ten and other industry security frameworks that stress the critical importance of validating all user inputs and system interactions.