CVE-2007-0613 in iChat
Summary
by MITRE
The Bonjour functionality in mDNSResponder, iChat 3.1.6, and InstantMessage framework 428 in Apple Mac OS X 10.4.8 does not check for duplicate entries when adding newly discovered available contacts, which allows remote attackers to cause a denial of service (disrupted communication) via a flood of duplicate _presence._tcp mDNS queries.
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Analysis
by VulDB Data Team • 03/02/2025
The vulnerability described in CVE-2007-0613 represents a critical flaw in Apple's Bonjour implementation within the mDNSResponder service and related instant messaging frameworks. This issue affects Mac OS X 10.4.8 and specifically targets the handling of mDNS queries within the iChat 3.1.6 and InstantMessage framework 428 components. The flaw manifests in the absence of duplicate entry validation when processing newly discovered contacts, creating a pathway for malicious actors to exploit the system's communication protocols. The vulnerability operates at the network layer, specifically targeting the Multicast DNS implementation that Bonjour relies upon for service discovery and contact management.
The technical mechanism behind this vulnerability involves the mDNS protocol's failure to implement proper duplicate detection when processing _presence._tcp service queries. When a remote attacker sends a flood of duplicate mDNS queries, the system's Bonjour functionality does not properly identify these repeated entries and continues to process them, leading to resource exhaustion and eventual disruption of communication services. This behavior constitutes a classic denial of service attack vector where the attacker can overwhelm the system's ability to handle legitimate network traffic. The vulnerability is particularly dangerous because it operates at the foundational level of network communication, affecting the core messaging infrastructure that users rely upon for instant messaging and contact discovery.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromising the entire communication ecosystem on affected systems. When the flood of duplicate queries overwhelms the mDNSResponder service, users experience disrupted communication capabilities within iChat and other applications that depend on the InstantMessage framework. The denial of service occurs not just at the application level but at the network protocol level, making it particularly challenging to mitigate. This vulnerability affects the availability aspect of the CIA triad by preventing legitimate users from establishing or maintaining communication sessions, while also potentially exposing the system to further exploitation attempts.
Security practitioners should implement immediate mitigations including network-level filtering to limit mDNS query flooding and monitor for unusual patterns of _presence._tcp queries. The vulnerability aligns with CWE-129, which addresses improper validation of input data, and reflects patterns seen in ATT&CK technique T1498, which involves denying service through resource exhaustion. Organizations should consider implementing rate limiting mechanisms on mDNS traffic and establishing monitoring protocols to detect abnormal query patterns. The flaw demonstrates the importance of proper input validation and duplicate detection in network protocols, as outlined in industry best practices for secure network service implementation. System administrators should also consider updating to patched versions of Mac OS X where available and implement network segmentation to limit the impact of potential exploitation attempts.