CVE-2006-4662 in ICQ
Summary
by MITRE
Heap-based buffer overflow in the MCRegEx__Search function in AOL ICQ Pro 2003b Build 3916 and earlier allows remote attackers to execute arbitrary code via an inconsistent length field of a Message in a 0x2711 Type-Length-Value (TLV) type.
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Analysis
by VulDB Data Team • 01/14/2025
The vulnerability identified as CVE-2006-4662 represents a critical heap-based buffer overflow affecting AOL ICQ Pro version 2003b Build 3916 and earlier implementations. This flaw exists within the MCRegEx__Search function, which processes regular expression searches within the messaging infrastructure of the ICQ client. The vulnerability arises from inadequate input validation when handling Message TLV structures, specifically those with type 0x2711, creating a condition where attacker-controlled data can overwrite adjacent memory regions in the heap allocation space.
The technical exploitation mechanism relies on the manipulation of length fields within TLV data structures, where an inconsistent length value can cause the MCRegEx__Search function to allocate insufficient memory for processing the message content. When the function attempts to copy data into the allocated buffer, it exceeds the boundaries of the heap-allocated memory segment, leading to memory corruption that can be leveraged for arbitrary code execution. This vulnerability falls under CWE-121 Heap-based Buffer Overflow, which specifically addresses buffer overflows occurring in heap memory regions where the buffer size is determined at runtime based on user-supplied data.
The operational impact of this vulnerability extends beyond simple code execution, as it provides remote attackers with the capability to gain complete control over affected systems running vulnerable ICQ clients. Attackers can craft malicious messages with malformed TLV structures that trigger the buffer overflow condition, potentially leading to privilege escalation, system compromise, or denial of service conditions. The remote nature of this attack vector means that adversaries do not require local access to exploit the vulnerability, making it particularly dangerous in networked environments where ICQ clients process messages from untrusted sources.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, as successful exploitation could enable attackers to execute arbitrary commands on compromised systems. The attack surface is particularly concerning given the widespread adoption of ICQ as an instant messaging platform, where users regularly receive messages from contacts and potentially untrusted sources. The vulnerability demonstrates poor input validation practices and inadequate memory management, characteristics commonly associated with legacy software systems that have not received proper security updates or code reviews.
Mitigation strategies for CVE-2006-4662 primarily involve immediate patching of affected ICQ client versions to the latest available security updates from AOL. Organizations should implement network segmentation to prevent unauthorized access to systems running vulnerable ICQ clients and consider disabling ICQ functionality in enterprise environments where it is not essential. Additionally, network monitoring should be enhanced to detect anomalous TLV message structures that could indicate exploitation attempts. The vulnerability serves as a reminder of the importance of regular security updates and proper input validation in preventing heap-based buffer overflow conditions that can lead to complete system compromise.