CVE-2007-0614 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 allows remote attackers to cause a denial of service (persistent application crash) via a crafted phsh hash attribute in a TXT key.
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Analysis
by VulDB Data Team • 03/02/2025
The vulnerability identified as CVE-2007-0614 resides within the Bonjour networking functionality implemented in Apple Mac OS X 10.4.8 systems. This issue affects multiple Apple applications including mDNSResponder, iChat 3.1.6, and the InstantMessage framework version 428. The core problem manifests when these applications process DNS Service Discovery (DNS-SD) records containing maliciously crafted phsh hash attributes within TXT key data structures. The Bonjour protocol, which enables zero-configuration networking, relies on multicast DNS for service discovery and is integral to Mac OS X networking operations. This vulnerability specifically targets the parsing logic within the mDNSResponder daemon that handles DNS TXT record processing, creating a condition where malformed input can trigger unexpected application behavior.
The technical flaw stems from insufficient input validation within the DNS TXT record parsing mechanism of the mDNSResponder service. When the system encounters a TXT record containing a crafted phsh hash attribute, the parsing routine fails to properly handle the malformed data structure, leading to memory corruption or stack overflow conditions. This type of vulnerability falls under CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read errors. The vulnerability is particularly dangerous because it allows remote attackers to exploit the service discovery mechanism without requiring local access or authentication. The phsh hash attribute specifically refers to a hash-based service discovery attribute that Apple uses for certain service identification purposes, but when malformed, it can cause the underlying parsing code to execute unintended memory operations. The attack vector operates through the multicast DNS protocol, where malicious actors can broadcast specially crafted DNS records to the local network segment, targeting systems running affected versions of Mac OS X.
The operational impact of this vulnerability extends beyond simple application crashes, creating persistent denial of service conditions that can severely impact network connectivity and user productivity. When exploited, the vulnerability causes affected applications to repeatedly crash and restart, effectively rendering the Bonjour service unavailable for legitimate network discovery operations. This disruption affects not only iChat and instant messaging functionality but also other applications that depend on DNS-SD for service discovery, including file sharing, printer discovery, and various networked applications. The persistent nature of the crashes means that even after the initial attack, the system remains unstable until manual intervention occurs, such as restarting the mDNSResponder service or rebooting the entire system. This vulnerability represents a significant concern for enterprise environments where Mac OS X systems rely heavily onBonjour for network operations and where persistent service availability is critical for business operations. The attack requires minimal technical expertise to execute, making it particularly dangerous as it can be exploited by attackers with basic networking knowledge.
Mitigation strategies for CVE-2007-0614 focus on both immediate patching and network-level protections. Apple released security updates for Mac OS X 10.4.9 and subsequent versions that addressed the input validation issues in the mDNSResponder service. Organizations should prioritize applying these patches to all affected systems and implement network segmentation to limit exposure to potentially malicious DNS records. Network administrators can also deploy monitoring solutions to detect unusual DNS traffic patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of robust input validation in network services, aligning with ATT&CK technique T1071.004 for application layer protocol: DNS, where attackers manipulate DNS records to achieve malicious objectives. Additionally, this vulnerability highlights the need for proper boundary checking in parsing routines and demonstrates how service discovery protocols can become attack vectors when not properly secured. System administrators should also consider implementing firewall rules that restrict multicast DNS traffic to trusted network segments and monitor for unusual DNS query patterns that might indicate exploitation attempts. The incident underscores the critical nature of maintaining up-to-date security patches and the potential for seemingly benign networking protocols to become significant security risks when input validation is inadequate.