CVE-2002-0362 in Instant Messenger
Summary
by MITRE
Buffer overflow in AOL Instant Messenger (AIM) 4.2 and later allows remote attackers to execute arbitrary code via a long AddExternalApp request and a TLV type greater than 0x2711.
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Analysis
by VulDB Data Team • 05/29/2019
The vulnerability identified as CVE-2002-0362 represents a critical buffer overflow flaw in AOL Instant Messenger version 4.2 and later implementations. This security weakness resides in the handling of external application requests within the AIM client software, specifically when processing AddExternalApp commands. The vulnerability stems from insufficient input validation and bounds checking mechanisms that fail to properly sanitize the TLV (Type-Length-Value) data structures used in the communication protocol. When a malicious actor crafts a specially formatted AddExternalApp request with a TLV type exceeding the legitimate maximum value of 0x2711, the application fails to properly validate this input, leading to memory corruption that can be exploited for arbitrary code execution.
The technical exploitation of this vulnerability involves crafting a malicious TLV packet where the type field exceeds the expected range of 0x2711, causing the application to write beyond the allocated buffer boundaries. This buffer overflow condition occurs during the parsing of external application requests, where the AIM client does not properly validate the length and type parameters before processing them. The flaw is classified as a classic stack-based buffer overflow according to CWE-121, which occurs when a program writes data beyond the boundaries of a fixed-length buffer allocated on the stack. This particular implementation vulnerability falls under the broader category of CWE-787, which describes out-of-bounds write conditions that can result in arbitrary code execution when attacker-controlled data is written to memory locations beyond the intended buffer limits.
From an operational perspective, this vulnerability presents a significant risk to users of AIM 4.2 and later versions, as it enables remote code execution without requiring any authentication or user interaction. Attackers can exploit this flaw by sending specially crafted AddExternalApp requests to targeted victims, potentially gaining full system control of the affected machines. The vulnerability's remote exploitability means that attackers do not need physical access to the target system, making it particularly dangerous in networked environments where AIM clients are actively communicating. The impact extends beyond individual user compromise to potentially enable broader network infiltration, as compromised AIM clients could serve as entry points for further attacks within corporate networks or personal computing environments. This vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter, as successful exploitation would allow attackers to execute arbitrary commands on compromised systems.
The mitigation strategies for CVE-2002-0362 primarily focus on immediate software updates and patches provided by AOL to address the buffer overflow condition. Organizations should implement network segmentation and firewall rules to restrict AIM traffic where possible, particularly blocking external AddExternalApp requests that could be used for exploitation. Additionally, network monitoring solutions should be configured to detect anomalous TLV type values and unusual AddExternalApp request patterns that may indicate exploitation attempts. System administrators should also consider implementing application whitelisting policies to restrict the execution of AIM and other instant messaging clients on critical network segments. The vulnerability underscores the importance of proper input validation and bounds checking in software development, particularly for applications handling external data inputs. Organizations should conduct regular security assessments of their messaging infrastructure and ensure that all client applications are kept up-to-date with the latest security patches. This vulnerability also highlights the risks associated with legacy software systems and the importance of migrating to more secure communication platforms that have been designed with modern security practices in mind. The flaw demonstrates how seemingly minor protocol implementation issues can result in critical security vulnerabilities that can be exploited remotely to achieve complete system compromise.