CVE-2006-0630 in The Bat
Summary
by MITRE
RITLabs The Bat! before 3.0.0.15 displays certain important headers from encapsulated data in message/partial MIME messages, instead of the real headers, which is in violation of RFC2046 header merging rules and allows remote attackers to spoof the origin of e-mail by sending a fragmented message, as demonstrated using spoofed Received: and Message-ID: headers.
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Analysis
by VulDB Data Team • 08/05/2017
The vulnerability identified as CVE-2006-0630 affects RITLabs The Bat! email client version 3.0.0.14 and earlier, presenting a significant security flaw in how the application processes MIME message fragments. This issue stems from the client's improper handling of message/partial MIME messages, which are designed to allow large messages to be broken into smaller parts for transmission. The flaw violates RFC 2046 standards that govern MIME message structure and header merging rules, creating a fundamental inconsistency in how email headers are processed and displayed.
The technical implementation of this vulnerability occurs when The Bat! receives a fragmented message that contains multiple parts with different headers. Instead of properly merging these headers according to RFC 2046 specifications, the client displays headers from the encapsulated data portions rather than the actual headers from the original message. This misbehavior specifically affects critical email headers such as Received: and Message-ID: which are essential for email authentication and tracking. The flaw enables attackers to craft malicious messages that appear to originate from legitimate sources by carefully manipulating the header information in the fragmented parts.
From an operational perspective, this vulnerability creates a serious spoofing attack vector that can be exploited by remote adversaries to compromise email integrity and authentication. Attackers can construct fragmented messages where the first part contains spoofed Received: headers that make it appear the message originated from a trusted source, while the subsequent parts contain the actual message content. This technique can be used to bypass email security controls, conduct phishing attacks, or manipulate email routing decisions based on false header information. The impact extends beyond simple deception as it undermines the fundamental trust model of email systems and can lead to successful social engineering campaigns.
The vulnerability aligns with CWE-200 (Information Exposure) and represents a specific implementation of header manipulation techniques that fall under ATT&CK tactic TA0001 (Initial Access) and technique T1192 (Spearphishing Attachment). The flaw demonstrates poor input validation and header processing within the MIME parsing component of the email client, creating a condition where the application fails to properly validate header information from fragmented messages. Organizations using affected versions of The Bat! are particularly vulnerable to attacks targeting email-based authentication systems, as the spoofed headers can bypass security measures that rely on header validation. The remediation requires updating to version 3.0.0.15 or later, which implements proper RFC 2046 compliance for header merging in MIME message processing. This vulnerability highlights the importance of proper MIME message handling in email clients and underscores the need for comprehensive testing of email parsing components against established standards to prevent similar header manipulation attacks.