CVE-2005-0127 in Mac OS X Server
Summary
by MITRE
Mail in Mac OS X 10.3.7, when generating a Message-ID header, generates a GUUID that includes information that identifies the Ethernet hardware being used, which allows remote attackers to link mail messages to a particular machine.
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Analysis
by VulDB Data Team • 11/21/2024
The vulnerability described in CVE-2005-0127 represents a significant privacy and security concern within the Mail application of Mac OS X 10.3.7. This issue stems from the improper generation of Message-ID headers during email composition, where the system incorporates hardware-specific identifiers into the unique message identifier. The flaw directly violates fundamental principles of email privacy and anonymity by creating a persistent link between email communications and specific network hardware configurations. When the Mail application generates a Message-ID, it includes a GUUID (Globally Unique Universal Identifier) that contains Ethernet hardware address information, effectively creating a fingerprint that can be used to correlate multiple email messages back to a particular machine or network interface. This vulnerability operates at the application layer of the network stack, specifically affecting the email client's header generation mechanism and represents a classic example of information disclosure through metadata.
The technical implementation of this flaw involves the Mail application's use of hardware-specific identifiers during the Message-ID creation process. When generating a GUUID for email headers, the system incorporates the MAC address or other Ethernet hardware identifiers, which are inherently tied to specific network interfaces. This approach fundamentally undermines the concept of globally unique identifiers by introducing deterministic elements that reveal system characteristics. The vulnerability can be categorized under CWE-200 (Information Exposure) and relates to improper entropy generation in identifier creation. From an operational perspective, this flaw enables attackers to perform passive correlation analysis across multiple email communications, allowing them to establish network attribution and potentially map communication patterns to specific individuals or systems. The attack surface is particularly concerning because email headers are typically visible to all parties in the communication chain, including intermediaries and potential eavesdroppers who may not be the intended recipients. This vulnerability aligns with ATT&CK technique T1566 (Phishing) and T1592 (Gather Victim Identity Information) as it provides attackers with additional means to identify and track targets through network metadata analysis.
The impact of this vulnerability extends beyond simple privacy concerns into areas of network security and forensic analysis. Attackers can leverage this information to build detailed profiles of email users by correlating messages over time, effectively creating a persistent tracking mechanism that operates even when other privacy measures are in place. The flaw particularly affects users in environments where network monitoring is present, as the hardware identifiers can be extracted from email headers and used to establish network attribution. This capability undermines the security assumptions of email communications and creates opportunities for targeted surveillance or tracking campaigns. Organizations using Mac OS X 10.3.7 systems may face increased risk of targeted attacks where adversaries can use this information to map communication patterns and potentially identify sensitive information flows. The vulnerability demonstrates the importance of proper entropy generation in identifier creation and highlights the need for robust privacy considerations in application development, particularly when dealing with metadata generation and network communication protocols. Mitigation efforts should focus on ensuring that all identifiers used in network communications are truly random and do not contain deterministic elements that reveal system characteristics, aligning with security best practices outlined in RFC 2822 for email header construction and general secure coding principles.