CVE-2004-0162 in MAILsweeper
Summary
by MITRE
Multiple content security gateway and antivirus products allow remote attackers to bypass content restrictions via MIME encapsulation that uses RFC822 comment fields, which may be interpreted as other fields by mail clients.
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Analysis
by VulDB Data Team • 06/21/2018
The vulnerability described in CVE-2004-0162 represents a critical flaw in content security gateways and antivirus products that process email traffic. This weakness stems from improper handling of MIME encapsulation techniques that utilize RFC822 comment fields, creating a pathway for malicious actors to circumvent security controls designed to filter and block harmful content. The vulnerability affects a wide range of security appliances and software solutions deployed by organizations to protect their email infrastructure from threats.
The technical root cause of this vulnerability lies in the way mail clients and security gateways interpret MIME (Multipurpose Internet Mail Extensions) structures. RFC822 comment fields, which are part of the email message format specification, can be manipulated by attackers to embed malicious content within legitimate email headers or body sections. When security products parse these messages, they may incorrectly interpret comment fields as other MIME fields, leading to improper content analysis and filtering decisions. This misinterpretation occurs because the parsing logic fails to properly validate or sanitize the structure of comment fields within the email message.
The operational impact of this vulnerability extends beyond simple bypass of content restrictions. Attackers can exploit this weakness to deliver phishing emails, malware attachments, or other malicious payloads that would normally be detected and blocked by security systems. The vulnerability is particularly dangerous because it operates at the protocol level where security controls are designed to be most effective. This allows threat actors to maintain persistence in email-based attack campaigns while evading detection mechanisms that rely on proper MIME structure validation. The bypass capability can result in significant data breaches, system compromises, and unauthorized access to sensitive organizational information.
Organizations implementing security solutions that are vulnerable to CVE-2004-0162 face substantial risk exposure, particularly in environments where email is a primary communication channel. The vulnerability aligns with CWE-119, which addresses improper restriction of operations within a memory buffer, as the issue involves incorrect handling of data structures during parsing operations. From an ATT&CK framework perspective, this vulnerability maps to techniques involving evasion of security controls and initial access through email-based attacks. The attack surface includes email security appliances, content filtering systems, and antivirus solutions that process email traffic in real-time.
Effective mitigations for this vulnerability require immediate updates to security appliance firmware and software to address the MIME parsing implementation flaws. Organizations should implement additional email validation layers that perform stricter MIME structure validation and ensure that comment fields are properly sanitized or ignored during content analysis. Network administrators should also consider implementing multiple defense-in-depth strategies including email authentication protocols like SPF, DKIM, and DMARC to complement traditional content filtering approaches. Regular security assessments of email infrastructure and continuous monitoring of email traffic patterns remain essential for early detection of exploitation attempts. Patch management procedures should be prioritized to ensure all content security gateways and antivirus systems receive timely updates addressing this specific vulnerability.