CVE-2004-1944 in Eudora
Summary
by MITRE
Eudora 6.1 and 6.0.3 for Windows allows remote attackers to cause a denial of service (crash) via a deeply nested multipart MIME message.
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Analysis
by VulDB Data Team • 08/03/2025
The vulnerability identified as CVE-2004-1944 affects Eudora email client versions 6.1 and 6.0.3 running on Windows operating systems. This issue represents a classic stack-based buffer overflow condition that manifests through malformed email content processing. The flaw specifically occurs when the email client encounters deeply nested multipart mime messages, which are legitimate email structures used to organize complex email content with multiple parts and subparts. The vulnerability stems from inadequate input validation and bounds checking within the email parsing routine that processes these nested structures.
The technical implementation of this vulnerability involves the email client's failure to properly handle recursive parsing of multipart mime messages. When processing a maliciously crafted email with excessive nesting levels, the application's internal buffer management becomes overwhelmed, leading to stack corruption and subsequent application crash. This behavior aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a fundamental flaw in memory management during recursive data structure processing. The vulnerability operates at the application layer and requires no special privileges to exploit, making it particularly dangerous as it can be triggered through normal email reception.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable more sophisticated attack vectors. While the immediate effect is a denial of service condition causing the email client to crash and restart, the underlying memory corruption could theoretically be exploited for more advanced attacks. The vulnerability affects users who receive emails from untrusted sources, making it particularly concerning in corporate environments where email is a primary communication channel. The issue demonstrates a lack of proper error handling and defensive programming practices in the email client's MIME parsing implementation, which violates security best practices outlined in the OWASP Top Ten and similar industry standards.
Mitigation strategies for this vulnerability include immediate application of vendor patches or updates to newer versions of Eudora that address the buffer overflow condition. System administrators should implement email filtering solutions that can identify and quarantine malformed emails before they reach end users. Network-based security controls such as email gateway filtering and content inspection can provide additional protection layers. The vulnerability also highlights the importance of input sanitization and proper bounds checking in email client applications, emphasizing the need for robust defensive programming techniques. Organizations should consider implementing email client hardening measures and regular security assessments to identify similar vulnerabilities in other email processing applications. This issue serves as a reminder of the critical importance of secure coding practices and proper input validation in preventing denial of service attacks that can compromise system availability and user productivity.