CVE-2004-2147 in Norton Antivirus
Summary
by MITRE
Unknown versions of Symantec Norton AntiVirus and Microsoft Outlook allow attackers to cause a denial of service (crash) via malformed e-mail messages (1) without a body or (2) without a carriage return ("\n") separating the headers from the body.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability described in CVE-2004-2147 represents a classic buffer overflow and input validation flaw that affected widely used security software products including Symantec Norton AntiVirus and Microsoft Outlook. This issue demonstrates how seemingly benign email formatting can be exploited to disrupt critical security infrastructure, highlighting the importance of robust input sanitization in email processing systems. The vulnerability specifically targets the email parsing mechanisms within these applications, where improper handling of malformed email structures leads to application instability and potential system crashes. The flaw exists in the way these applications process email headers and body content, particularly when encountering emails that lack standard formatting elements such as message bodies or proper header-body delimiters.
The technical implementation of this vulnerability stems from inadequate boundary checking and input validation within the email processing modules of these applications. When Symantec Norton AntiVirus or Microsoft Outlook encounters an email message lacking either a message body or a carriage return character that properly separates headers from the body, the parsing routine fails to handle these edge cases gracefully. This leads to memory corruption or stack overflow conditions that cause the application to terminate unexpectedly. The vulnerability is categorized under CWE-129 Input Validation and Output Encoding, specifically addressing improper validation of input data that results in buffer overflows. The flaw operates at the application layer of the network stack, making it particularly dangerous as it can be exploited through simple email delivery without requiring any special privileges or complex attack vectors.
The operational impact of CVE-2004-2147 extends beyond simple denial of service, as it can significantly compromise security operations and productivity within organizations. When email applications crash repeatedly due to malformed messages, users lose access to critical communication channels and security tools become ineffective at scanning incoming mail. This vulnerability particularly affects enterprise environments where email systems serve as primary communication channels and security monitoring tools process large volumes of incoming messages. The attack vector is relatively simple, requiring only the delivery of specially crafted email messages that exploit the parsing logic, making it an attractive target for threat actors seeking to disrupt business operations or create distractions during more sophisticated attacks. Organizations using these vulnerable versions face potential exposure to both direct service disruption and indirect security risks.
Mitigation strategies for this vulnerability require immediate patching of affected software versions, as the flaw represents a fundamental design weakness in the email processing logic. System administrators should implement email filtering rules that identify and quarantine suspicious email formats before they reach vulnerable applications. Network-level protections can include implementing email scanning appliances that preprocess messages to normalize email formatting before delivery to end-user applications. The recommended approach involves applying vendor security patches immediately, as Symantec and Microsoft would have released updates addressing the specific parsing logic flaws. Additionally, organizations should implement email hygiene practices such as regular security updates, email header validation, and monitoring for unusual email traffic patterns that might indicate exploitation attempts. This vulnerability serves as a reminder of the critical importance of input validation in security applications and the need for comprehensive testing of edge cases in email processing systems. The flaw aligns with ATT&CK technique T1499.004 for denial of service attacks and demonstrates how basic application logic flaws can create significant operational disruptions.